Business Statistics
What does Excel have the capability to compute? Choose the correct option and select Submit.
-Variance -Standard deviation -Mean (all of the above)
What does the total of the probabilities of each value in the probability distribution always equal? Choose the correct option and select Submit.
1
The value of |-20| is what? Choose the correct option and select Submit.
20
Which of the following is a point estimate? Choose the correct option and select Submit.
A sample statistic that represents a population parameter
Outlier
A value that is either much larger or much smaller than the rest of the data.
The margin of error that is considered acceptable in an experiment.
Allowable error
A source of variation that has the potential to influence all observations.
Common cause variation
The outcome or outcomes that do not occur when an experiment is conducted.
Complement
A group of outcomes.
Event
The shape of the chi-square distribution depends on the size of the sample. Select one: True False
False
The strength of the correlation between two variables depends on the sign of the coefficient of correlation. Select one: True False
False
A situation in which the difference between an estimate of the dependent variable and its actual value is approximately the same for all observations.
Homoscedasticity
Arithmetic mean
In a population, it is the sum of all the values divided by the number of items. In a sample, it is the sum of the value of the items selected divided by the number of items.
When variables have an inverse relationship, how do they move? Choose the correct option and select Submit.
In the opposite direction
The concept that event A or event B includes events A and B.
Inclusive
The highest value in a distribution.
Maximum
After correcting an out-of-control situation, you remove the subgroup with the assignable cause and then __________. Choose the correct option and select Submit.
Rerun the control chart
A sampling technique where the population is divided into groups and all groups are randomly tested is called what? Choose the correct option and select Submit.
Stratified random sampling
What is the purpose of a contingency table? Choose the correct option and select Submit.
Summarize observations
A special distribution that is continuous, bell-shaped, and symmetrical. It is more spread out at the center than a normal distribution.
T distribution
What computes the coefficient of determination? Choose the correct option and select Submit.
Taking the square of the coefficient of correlation
A value determined from the sample data that tests the hypotheses.
Test statistic
Variance
The arithmetic mean of the squared deviations of the observations from the mean.
To compute SS, take the difference between each observation and what? Choose the correct option and select Submit.
The grand mean
Maximum
The highest value in a distribution
Choose the correct option and select Submit.
The hypothesized population proportion
When computing the F value, the numerator is always what? Choose the correct option and select Submit.
The largest variation value
Minumum
The lowest value in a distribution.
To compute the mean of a probability distribution, you multiply the value by what? Choose the correct option and select Submit.
The probability of that value occurring P(x)
When computing a sample mean, what is the calculation? Choose the correct option and select Submit.
The same as the population mean
Statistics
The science of gathering, organizing, analyzing, and presenting data.
A nonparametric test used to compare two independent populations.
Wilcoxon rank sum test
A population consists of all the weights of all defensive tackles on a university's football team. They are Johnson, 204 pounds; Patrick, 215 pounds; Junior, 207 pounds; Kendron, 212 pounds; Nicko, 214 pounds; and Cochran, 208 pounds. What is the population standard deviation (in pounds)? Select one: a. About 4 b. About 16 c. About 100 d. About 40
a. About 4
An automatic machine inserts mixed vegetables into a plastic bag. Past experience revealed that some packages were underweight and some were overweight, but most of them had satisfactory weight. Weight% Of TotalUnderweight2.5Satisfactory90.0Overweight7.5 What is the probability of selecting three packages that are satisfactory? Select one: a. 0.900 b. 0.810 c. 0.729 d. 0.075
c. 0.729
A sample of 250 adults tried the new multigrain cereal "Wow!" A total of 187 rated it as excellent. In a sample of 100 children, 66 rated it as excellent. Using the 0.1 significance level, the researcher wishes to show that adults like the cereal better than children. Which of the following is the alternate hypothesis? Select one: a. H1: πA = πC b. H1: πA < πC c. H1: πA > πC d. H1: πA ≠ πC
c. H1: πA > πC
If the null hypothesis that two means are equal is true, where will 97% of the computed z values lie between? Select one: a. ±2.58 b. ±2.33 c. ±2.17 d. ±2.07
c. ±2.17
The number of scores that are free to vary when calculating a statistic.
df
The F distribution cannot have a value of what? Choose the correct option and select Submit.
-1
Using Pearson's coefficient of skewness, the value should be between what? Choose the correct option and select Submit.
-3 to 3
Which of following are techniques that can be used to distort polling results? Choose the correct option and select Submit.
-A non-random sample -Biased or leading questions -Inappropriate sample size (all of the above)
z statistic is greater than the critical value, what should you do? Choose the correct option and select Submit.
-Accept the alternative hypothesis -Reject the null hypothesis (Both of the above)
Take a moment to review the tools of analysis in this short exercise. What does a tree diagram display? Choose the correct option and select Submit.
-All possible outcomes -Conditional probabilities -Joint probabilities (All of the above)
Choose the correct option and select Submit.
-Based on a infinite population -Less than 5% of the population (either of the above)
Statistics are used by and affect what? Choose the correct option and select Submit.
-Corporations -Individuals -Government agencies (all of the above)
Statistics on how your class performed on a statistics test is what? Choose the correct option and select Submit.
-Descriptive statistics
To use the ANOVA technique, the populations must have what? Choose the correct option and select Submit.
-Equal standard deviations -A normal distribution -Independence from each other (All of the above)
Take a moment to practice use of statistics concepts in this short exercise. The science of statistics involves what? Choose the correct option and select Submit.
-Gathering data -Presenting data -Organizing data (all of the above)
When creating subgroups, what is an important factor to consider? Choose the correct option and select Submit.
-How they are selected -The size of the subgroups -The frequency of the subgroup selection (All the above)
Statistics on what percent of the population favors gun control is called what? Choose the correct option and select Submit.
-Inferential statistics
MegaStat has the capability to compute what? Choose the correct option and select Submit. To check your answers, select Show Me.
-Kruskal-Wallis H test -Spearman's rank correlation coefficient -The Wilcoxon tests (All the above)
In a normal probability distribution, you find what value at the center point of the distribution? Choose the correct option and select Submit.
-Mean -Median -Mode (All of the above)
To compute Pearson's coefficient of skewness, what do you need? Choose the correct option and select Submit.
-Median of the sample -Standard distribution of the sample -Mean of the sample (all of the above)
What is the Excel function that is used to compute a Poisson probability distribution? Choose the correct option and select Submit.
-POISSONDIST -Megastat -Minitab (None of the above!!!!!)
What is the Excel function used to compute a binomial probability distribution? Choose the correct option and select Submit.
-PROB -PROBDIST -DIST (None of the above!!!!!!)
To compute a prediction interval, you need to know the values for what? Choose the correct option and select Submit.
-Predicted value of Y (Y') -The mean of X -t value (all of the above)
Statistical process control is a procedure that strives to what? Choose the correct option and select Submit
-Prevent quality problems -Decrease process variation -Increase quality (All the above)
When determining a sample size, what is an important factor to consider? Choose the correct option and select Submit.
-The confidence level -The allowable error -The dispersion of the data (all of the above)
What do you need to provide when using Excel to compute a confidence interval? Choose the correct option and select Submit.
-The input range for the data -The confidence level for the mean (Both of the above)
Dot plots allow you to see which of the following? Choose the correct option and select Submit.
-The minimum value -The maximum value -The distribution shape (all of the above)
What do you need to compute the standard deviation of a uniform distribution? Choose the correct option and select Submit.
-The minimum value of the distribution (a) -The maximum value of the distribution (b) (Both of the above)
A sampling distribution of the sample mean table shows _______. Choose the correct option and select Submit.
-The number of times the mean appears in the sample data -The probability of a sample being chosen -All possible sample combinations (all the above)
What do you need to know to use the binomial probability distribution table? Choose the correct option and select Submit.
-The number of trials (n) -The number of successes (x) -The probability of an outcomes success (π) (All of the above)
The Spearman's correlation coefficient test ranks what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
-The observation values within a population -The differences in the observation values between populations (both of the above)
To test a hypothesis for a population proportion, what must be true? Choose the correct option and select Submit.
-The sample data must come from counting something. -The trial must be independent. -The probability of success must remain constant. (All of the above)
What is the risk of using a sample of a population instead of doing a census of the entire population? Choose the correct option and select Submit.
-The sample is not representative of the entire population -The sample might be biased -Population parameters usually differ from the statistics (all of the above)
What do you need to know to compute a confidence interval for a large sample? Choose the correct option and select Submit.
-The sample mean -Number of observations -The standard deviation of the sample mean (All of the above)
When computing the number of possible combinations of values in a sample, we use _______. Choose the correct option and select Submit.
-The size of the population -The sample size -Factorials (all of the above)
If the standard deviation of the population is not known, what should the researcher consider? Choose the correct option and select Submit.
-Using the standard deviation from a comparable study -Taking an educated guess -Using the sample standard distribution -The dispersion of the data (all of the above)
Take a moment to practice Poisson probability distribution concepts in this short exercise. A Poisson probability distribution has which of these characteristics? Choose the correct option and select Submit.
-You are tracking the number of times something occurs in a period -The events are independent -The probability of an event occurring is in proportion to the size of the period (All of the above)
To compute the mean of a uniform distribution, divide the total of the highest (b) and lowest (a) values in the distribution by what? Choose the correct option and select Submit.
-x -μ (Neither of these)
The Poisson probability distribution formula requires you to know the value of what? Choose the correct option and select Submit.
-x -μ Both of these
What is a typical level of significance? Choose the correct option and select Submit.
.01
If you toss a dice, what is the probability of getting the number 2? Choose the correct option and select Submit.
.167
If 7 out of 10 students love statistics class, what is the proportion who love it? Choose the correct option and select Submit.
.70
If the LCL can not be computed, you should give it a value of __________. Choose the correct option and select Submit.
0
Take a moment to practice probability approaches by completing this short exercise. If an outcome will definitely occur, what is its probability? Choose the correct option and select Submit.
1
The total of all the probabilities of a distribution must equal what? Choose the correct option and select Submit.
1
Which of the following is a pattern you are concerned with when analyzing a control chart? Choose the correct option and select Submit.
1 point › 3 standard deviations from the center line
Take a moment to practice the geometric mean concepts in this short exercise. To compute the 4th root of a number, you take it to what? Choose the correct option and select Submit.
1/4 power (.25)
For purposes of the sign test, you can consider a large sample to be what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
10 observations
Take a moment to practice arithmetic mean concepts in this short exercise. What is the mean of the data set 5, 10, 15, 30? Choose the correct option and select Submit.
15
Take a moment to practice probability calculation concepts in this short exercise. How many possible outcomes does a binomial probability distribution trial have? Choose the correct option and select Submit.
2
Take a moment to practice median and mode concepts in this short exercise. Use the following population data for the first few questions: 10, 20, 20, 30, 40, and 50. What is the mode of the data? Choose the correct option and select Submit.
20
Take a moment to practice median and mode concepts in this short exercise. Use the following population data for the first few questions: 10, 20, 20, 30, 40, and 50. What is the median of the data? Choose the correct option and select Submit.
25
Take a moment to practice median and mode concepts in this short exercise. Use the following population data for the first few questions: 10, 20, 20, 30, 40, and 50. What is the arithmetic mean of the data? Choose the correct option and select Submit.
28.33
Choose the correct option and select Submit.
5
What is the complement of 40%? Choose the correct option and select Submit.
60%
Take a moment to practice normal probability distribution concepts in this short exercise. According to the empirical rule, approximately what percent of a standard normal distribution is within +2 or -2 standard deviations of the mean? Choose the correct option and select Submit.
95%
Weighted mean
A computation of the arithmetic mean used when you have multiple observations of the same value in the population or sample.
Regression analysis enables you to estimate the value of what? Choose the correct option and select Submit.
A dependent variable
What does a low p -value indicate? Choose the correct option and select Submit.
A high probability that the null hypothesis is not true.
What does the letter e in the Poisson probability distribution formula represents? Choose the correct option and select Submit.
A numeric constant
What is a treatment? Choose the correct option and select Submit.
A population that is tested
Sample
A portion or a subset selected from a population.
Take a moment to practice skewness concepts in this short exercise. Using Pearson's coefficient of skewness, what does a value of 1.00 indicate? Choose the correct option and select Submit.
A positive skew
What is a confidence interval? Choose the correct option and select Submit.
A range of values
geometric mean
A special form of a mean used in a situation in which you are computing averages that compound on each other or you want to compute the rate of change of an item over time.
A Spearman's correlation coefficient value of .90 indicates what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
A strong positive correlation
What does a coefficient of correlation of 0.85 indicate? Choose the correct option and select Submit.
A strong positive correlation
Which of the following situations cause an out-of-control situation? Choose the correct option and select Submit.
A subgroup data plot above the UCL
What do you use to compute the confidence interval of a small sample instead of a z value? Choose the correct option and select Submit. A d value A t value A r value A p value
A t value
The median of a distribution represents what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
A value below which 50% of the values falls
Analysis of variance table that contains data on the relationship between variables
ANOVA
Analysis of variance table that contains data on the relationship between variables.
ANOVA
If a null hypothesis is rejected, what should you do? Choose the correct option and select Submit.
Accept the alternative hypothesis
Parameter
Actual population value.
A statement that is accepted if testing indicates that the null hypothesis is false.
Alternative hypothesis
When computing the coefficient of correlation, what does a value of -2 indicate? Choose the correct option and select Submit.
An error in the calculation
Take a moment to practice using software to compute descriptive statistic concepts in this short exercise. Before using Excel for descriptive statistics, you might have to set it up using what? Choose the correct option and select Submit.
Analysis Tool Pak
What does ANOVA stands for? Choose the correct option and select Submit.
Analysis of variance
Take a moment to practice sampling errors concepts in this short exercise. Sampling errors _______. Choose the correct option and select Submit.
Are reduced if the sample size increases
In a population, it is the sum of all the values divided by the number of items. In a sample, it is the sum of the value of the items selected divided by the number of items.
Arithmetic mean
A process is considered to be in statistical control when what is eliminated? Choose the correct option and select Submit.
Assignable cause variation
A source of variation that is an intermittent or a permanent change in process that does not affect all observations.
Assignable cause variation
Variables appear to have a relationship to each other but one variable does not necessarily cause a change in the other item.
Association
If you only have two cells, to use chi-square the expected frequency of each cell must be what? Choose the correct option and select Submit. To check your answers, select Show Me.
At least 5
According to Chebyshev's Theorem, what is the percent of the data that lies within four standard deviations of the mean? Choose the correct option and select Submit.
At least 94%
Consists of observations of the dependent variable that tend to run in a pattern. This is a particular danger with data collected over a time sequence (time series).
Autocorrelation
What is the situation called if the independent variables are correlated? Choose the correct option and select Submit.
Autocorrelation
A Microsoft Excel function used to compute the binomial probability distribution.
BINOMDIST
A population with two modes.
Bi-Modal
What is the data set if a data set has two values that occur most often? Choose the correct option and select Submit.
Bi-modal
A probability distribution of outcomes that will have only two possible values.
Binomial probability distribution
Take a moment to practice bivariate concepts in this short exercise. What is studying the relationship of two variables called? Choose the correct option and select Submit.
Bivariate
The relationship between two variables.
Bivariate
What is a contingency table used with? Choose the correct option and select Submit.
Both nominal and ordinal data
A graphical image of quartile data.
Box plot
A line on a control chart that represents the average process performance when the process is in statistical control.
CNL
An Excel function that can be used to determine the number of possible combinations in a sample.
COMBIN
What is the Excel function that gives you all the combinations of a population with given sample size? Choose the correct option and select Submit.
COMBIN
What Excel function is used to compute the coefficient of correlation? Choose the correct option and select Submit.
CORREL
A process that can meet specifications.
Capable
A way to measure the category that a sample characteristic is classified into.
Categorical
Take a moment to practice ethics in this short exercise. An item causing a change in another item is an example of what? Choose the correct option and select Submit.
Causation
The frequency categories used in chisquare testing.
Cells
A test used to compare a nominal data frequency distribution to an expected frequency distribution. Also referred to as the goodnessoffit test.
Chi-square test
What approach was used to solve the preceding question? Choose the correct option and select Submit.
Classical
A sampling technique where the population is divided into groups and a group or groups are chosen randomly to be sampled is called what? Choose the correct option and select Submit.
Cluster sampling
An analytical tool used to measure the strength of the relationship between two interval-scale or ratio-scale variables. Values range between -1 and 1 and measure if the relation between two variables is direct, inverse, or independent.
Coefficient of correlation
An analytical tool that measures the amount of variation in the dependent variable that is attributable to the independent variable.
Coefficient of determination
A formula that tells you the percent of the total variance attributable to the regression.
Coefficient of multiple determination
What tells you the percentage of the variance attributable to the regression? Choose the correct option and select Submit.
Coefficient of multiple determination
An event occurs each time the experiment is conducted.
Collectively exhaustive
To compute the expected frequency for a cell in a contingency table, multiply the row total by what and then divide by the table total? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
Column total
A selection of objects from a group of objects, in which the order of the selected objects does not matter.
Combination
Take a moment to practice computing the number of possible outcome concepts in this short exercise. When combining two items and the order is not important, you should use what type of formula? Choose the correct option and select Submit.
Combination
A poorly trained worker might cause what type of variation? Choose the correct option and select Submit.
Common cause variation
The probability that one event is affected by the occurrence of another event.
Conditional probability
A range of sample data values that has a specified probability of containing a population parameter.
Confidence interval
The probability of a population parameter falling within the confidence interval.
Confidence level
A way to choose items one after another in order.
Consecutively
A table used to classify data according to two characteristics.
Contingency table
Variables that can assume any value within a given range are called what? Choose the correct option and select Submit.
Continuous
A probability distribution created by organizing continuous random variables.
Continuous probability distribution
Random variables that assume any value within a defined range. There are an infinite number of values that the variables take within this range.
Continuous random variables
When using Minitab to create control charts, you go to the Stats menu and then click __________. Choose the correct option and select Submit.
Control Charts
A quality control tool that graphically displays process performance.
Control chart
To create a correlation matrix using Excel, go to the menu bar and select Tools, Data Analysis, and what? Choose the correct option and select Submit.
Correlation
The study of the relationship between two or more variables.
Correlation analysis
Multicollinearity refers to what? Choose the correct option and select Submit.
Correlation between independent variables
Value used to make decisions about the null hypothesis. It divides the points between the true and false values.
Critical value
To access descriptive statistics in Excel, you go to the Tools menu and choose what? Choose the correct option and select Submit.
Data Analysis
Divides the data into 10 equal parts (10% each).
Decile
When the data is divided into 10 even parts, it is referred to as: what? Choose the correct option and select Submit.
Deciles
A rule that determines if the hypothesis should be accepted or rejected.
Decision rule
A variable that is predicted by the analysis.
Dependent variable
Statistics that organize, summarize, and present data.
Descriptive statistics
The process of describing important characteristics of a data set is called what? Choose the correct option and select Submit.
Descriptive statistics
The difference between two items.
Deviation
Variables that can assume only certain values are called what? Choose the correct option and select Submit.
Discrete
A probability distribution created by organizing discrete random variables.
Discrete probability distribution
Random variables that assume only certain values within a defined range. There are a finite number of values that the variables take within this range.
Discrete random variables
The variation or spread of the data.
Dispersion
When looking up a z value in the area under the normal curve table, you take the confidence level and do what? Choose the correct option and select Submit.
Divide it by two and look for its decimal value in the table
A value, such as 1 or 0, used to represent nominal scale variables data.
Dummy value
When a value, such as 0 or 1, is used to represent quantitative variables, what is the variable value called? Choose the correct option and select Submit.
Dummy value
A variable that holds dummy values.
Dummy variable
A rule that states that approximately 68% of the distribution will be within + or - 1 standard deviation of the mean, 95% of the distribution will be within + or - 2 standard deviations of the mean, and 99.7 of the distribution will be within + or - 3 standard deviations of the mean.
Empirical rule
The mean of all possible sample means should _______. Choose the correct option and select Submit.
Equal the mean of the population
The portion of the total variance that is not attributable to the regression.
Error variance
All observations will be placed in a category. For example, a person would be placed into the male or female category. They must go in one of the two categories. There are no other possibilities.
Exhaustive
A process that leads to the occurrence of an outcome.
Experiment
A probability distribution used in variance analysis. It is named for a famous statistician, Sir Ronald Fisher.
F distribution
A confidence interval for a population proportion uses the uniform distribution to approximate the binomial distribution. Select one: True False
False
A p-value is the same as a stated significance level. Select one: True False
False
A point estimate is a range of values used to estimate a population parameter. Select one: True False
False
A sample of 2,000 union members was selected, and a survey recorded their opinions regarding a proposed management union contract. A total of 1,600 members were in favor of it. A 95% confidence interval estimated that the population proportion was between 0.78 and 0.82. This indicates that about 80 out of 100 similarly constructed intervals would include the population proportion. Select one: True False
False
A scatter plot is a useful graphical method to determine if a set of sample data is from a normal population. Select one: True False
False
A statistics professor wants to compare grades in two different classes of the same course. This is an example of a paired sample. Select one: True False
False
A student scored in the 85th percentile on a standardized test. This means that the student scored lower than 85% of all students who took the test. Select one: True False
False
A z statistic is used for a problem involving any sample size and an unknown population standard deviation. Select one: True False
False
According to Chebyshev's Theorem, 75% of the observations lie within plus and minus 2.00 average mean deviations. Select one: True False
False
An F distribution is useful for testing the null hypothesis that a set of sample data is normally distributed. Select one: True False
False
An example of a dummy variable is "time to product's first repair" in years. Select one: True False
False
An interval estimate is a single value used to estimate a population parameter. Select one: True False
False
Extremely high or low scores affect the value of the median. Select one: True False
False
For a contingency table, the expected frequency for a cell is found by dividing the row total by the grand total. Select one: True False
False
If a confidence interval for the difference between a pair of treatment means includes 0, then we reject the null hypothesis that there is no difference in the pair of treatment means. Select one: True False
False
If the null hypothesis states that there is no difference between the mean income of males and the mean income of females, then the test is one-tailed. Select one: True False
False
If the sampling distribution of the sample means approximates a normal distribution, then the population is normally distributed. Select one: True False
False
If we select 100 persons from 25,000 registered voters and question them about candidates and issues, the 100 persons are referred to as the population. Select one: True False
False
In a Poisson distribution, the probability of success may vary from trial to trial. Select one: True False
False
In an ANOVA table, k represents the total number of sample observations and n represents the total number of treatments. Select one: True False
False
In multiple regression analysis, a residual is the difference between the value of an independent variable and its corresponding dependent variable value. Select one: True False
False
Multiple regression analysis is used when one independent variable is used to predict values of two or more dependent variables. Select one: True False
False
One assumption underlying linear regression is that the X values are normally distributed. Select one: True False
False
One characteristic of the F distribution is that the computed F can only range between -1 and +1. Select one: True False
False
Quartiles divide a distribution into 10 equal parts. Select one: True False
False
Some normal probability distributions are positively skewed. Select one: True False
False
The 50th percentile of a distribution is the same as the distribution mean. Select one: True False
False
The alternative hypothesis used in ANOVA is H1: All population means are equal. Select one: True False
False
The binomial probability distribution is always negatively skewed. Select one: True False
False
The central limit theorem states that for a sufficiently large sample the sampling distribution of the means of all possible samples of size n generated from the population will be approximately normally distributed with the mean of the sampling distribution equal to σ2 and the variance equal to σ2/n. Select one: True False
False
The claim that "male and female students at Coastal Carolina University prefer different parking lots on campus" is an example of a chi-square null hypothesis. Select one: True False
False
The coefficient of determination is the square root of the coefficient of correlation. Select one: True False
False
The coefficient of skewness is the standard deviation divided by the mean. Select one: True False
False
The confidence interval has a wider range of values than the prediction interval. Choose the correct option and select Submit.
False
The hypothesis to test the slope of a regression equation is H0: α = 0. Select one: True False
False
The number of different standard normal distributions is unlimited. Select one: True False
False
The order that runners finish in a race would be an example of continuous data. Select one: True False
False
The ordinal level of measurement is considered the "lowest" level of measurement. Select one: True False
False
The variance is the mean of the sum of the squared deviations between each observation and the median. Select one: True False
False
The z-scores for X values greater than the mean are negative. Select one: True False
False
When dependent samples are used to test for differences in the means, we pool the sample variances. Select one: True False
False
When using stratified random sampling, the sampling error will be zero. Select one: True False
False
An adjustment made to the confidence interval calculation for a finite population. This adjustment is usually ignored if less than 5% of the population is sampled. It applies to confidence intervals for proportions, z scores, and t scores.
Finite-population correction
Choose the correct option and select Submit.
Finite-population correction factor
If you want to know the probability of at least one of two or more independent events occurring, what would you use? Choose the correct option and select Submit.
General rule of addition
A special form of a mean used in a situation in which you are computing averages that compound on each other or you want to compute the rate of change of an item over time.
Geometric mean
The mean of all sample observations (also referred to as the overall mean).
Grand mean
Take a moment to practice the Chebyshev's Theorem and the empirical rule concepts in this short exercise. For Chebyshev's Theorem to work, what must the value of k (number of standard deviations) be? Choose the correct option and select Submit.
Greater than 1
A situation in which a geometric mean is used involves computing the mean of what? Choose the correct option and select Submit.
Hourly wages growth over a period of years
The process of sampling the population and using probability theories to determine if the hypothesis is reasonable.
Hypotesis testing
A statement made about a population that can be tested.
Hypothesis
The occurrence of an event has no effect on the occurrence of another event.
Independent
A variable used to compute dependent variable values. It is sometimes referred to as a predictor or explanatory variable.
Independent variable
Statistics that determine something about an entire group (population) based on looking at a part of the group (sample).
Inferential statistics
Take a moment to practice quartiles, deciles, and percentiles concepts in this short exercise. On a box plot, what is the area between Q1 and Q3 called? Choose the correct option and select Submit.
Interquartile range
The interval that contains 50% of the measurements. It is defined as Q3 - Q1.
Interquartile range
The level of measurement where zero is simply a value and not an absence of characteristic is called what? Choose the correct option and select Submit.
Interval
Which of the following is true about the F distribution? Choose the correct option and select Submit.
It has a positive skew.
A regression line will not contain all the data points because of what? Choose the correct option and select Submit.
It is an estimate.
Why would an average be misleading to a user? Choose the correct option and select Submit.
It may include extremely high or low values
Which of the following is an advantage of sampling compared to doing a census of the whole population? Choose the correct option and select Submit.
It saves time and money.
The probability of two or more events occurring.
Joint probability
A nonparametric test that compares three or more independent populations.
Kruskal-Wallis H test
A line on a control chart that represents the lower limit of the control area.
LCL
In computing the confidence and prediction intervals, the t value is not necessary in what? Choose the correct option and select Submit.
Large samples
The amount that the z value of a process exceeds the specifications of the process.
Leeway
What is the amount a z value exceeds 3 called? Choose the correct option and select Submit.
Leeway
A small sample is generally considered to be what? Choose the correct option and select Submit.
Less than 30
The dispersion between the highest and lowest sample means should be _______. Choose the correct option and select Submit.
Less than the dispersion between the highest and lowest population values
The probability of rejecting the null hypothesis when it should be accepted.
Level of significance
For regression analysis to be valid, what kind of relationship must be between the dependent and independent variables? Choose the correct option and select Submit.
Linear
A situation where data can be represented with a straight line.
Linear relationship
An abbreviation for Mean Square, which is computed by dividing the sum of square (SS) value for each row by its degrees of freedom (df)
MS
Tells you the amount of the variance between each observation and the overall mean attributable to randomness (stands for mean square error and also referred to as the error).
MSE
Tells you the amount of variance between each observation and the overall mean attributable to the treatments (stands for mean square treatment).
MST
A measure of central measurement that is computed by summing all the values and dividing by the number of items. Commonly referred to as an average or the expected value.
Mean
The arithmetic mean of the absolute values of the deviation of each observation from the arithmetic mean.
Mean deviation
The midpoint of the values after they have been arranged in order, either smallest to largest or largest to smallest.
Median
The lowest value in a distribution.
Minimum
The value of an observation that occurs most frequently.
Mode
The decision rule for a contingency table is to reject the null hypothesis if the test statistic is what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
More than the chi-square value
The correlation between independent variables.
Multicollinearity
Analysis involves more than one independent variable.
Multiple regression
The typical error that occurs in multiple regression analysis when predicting the dependent variable
Multiple standard error of estimate
In random sampling with replacement, how many times can you pick an item? Choose the correct option and select Submit.
Multiple times
When you have two or more sets of items from which you are choosing a grouping, what should you use? Choose the correct option and select Submit.
Multiplication formula
When the occurrence of one event prevents the other events from occurring.
Mutually exclusive
An Excel formula that computes the probability of an event occurring in a normal distribution.
NORMDIST
What Excel function is used to compute a normal probability distribution value? Choose the correct option and select Submit.
NORMDIST
A committee of 5 members is chosen from 8 men and 7 women. How many different committees can be formed? Select one: a. 77 b. 3003 c. 360 d. 1176 e. 280
NOT D
A local company wants to evaluate their quality of service by surveying their customers. Their budget limits the number of surveys to 100. What is their maximum error of the estimated mean quality for a 95% level of confidence and an estimated standard deviation of 5? Select one: a. 0.9604 b. 0.98 c. 1.96 d. 5%
NOT a. 0.9604
The average cost of tuition and room and board at a small private liberal arts college is reported to be $8,500 per term, but a financial administrator believes that the average cost is higher. A study conducted using 350 small liberal arts colleges showed that the average cost per term is $8,745. The population standard deviation is $1,200. Let α = 0.05. What is the test statistic for this test? Select one: a. ±3.82 b. +0.204 c. -3.82 d. +3.82
NOTTT: a. ±3.82
Which of the following is correct about a probability distribution? Select one: a. The sum of all possible outcomes must equal 1.0. b. Outcomes must be mutually exclusive. c. The probability of each outcome must be between 0.0 and 1.0 inclusive. d. All apply.
NOTTTTT c. The probability of each outcome must be between 0.0 and 1.0 inclusive.
A set of limits between which almost all the process measurements should fall.
Natural tolerance limits
The arithmetic mean is smaller than the median or mode because of one or more small values.
Negatively skewed distribution
The level of measurement where you present only the data is called what? Choose the correct option and select Submit.
Nominal
Statistical methods that do not require an assumption about the distribution shape are called what? Choose the correct option and select Submit. To check your answers, select Show Me.
Non-parametric distributions
What type of data is a p chart used to analyze? Choose the correct option and select Submit.
Nonconforming
In the sample size formula, what does the letter E represent? Choose the correct option and select Submit.
None of the above
The formula for the degrees of freedom in a contingency table is the number of rows - 1 multiplied by what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
None of the above
What does the regression equation predict? Choose the correct option and select Submit.
None of the above
What is the formula for the regression equation? Choose the correct option and select Submit.
None of the above
What is the formula to compute the proportion (p)? Choose the correct option and select Submit.
None of the above
When working with the correlation matrix, a value approaching -1 indicates what? Choose the correct option and select Submit.
None of the above
Which of these characteristics describes the chi-square distribution? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
None of the above
Compute the grand mean by totaling all the observations and dividing by what? Choose the correct option and select Submit.
None of the above.
What does the letter k in ANOVA analysis represent? Choose the correct option and select Submit.
None of the above.
Both of the Wilcoxon tests are what? Choose the correct option and select Submit. To check your answers, select Show Me.
Nonparametric
When using MegaStat to conduct a sign test, choose from the menu MegaStat and then what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
Nonparametric Tests
Statistical method that does not assume a normal distribution (or any other specific distribution) in the sampled population.
Nonparametric method
A distribution of data that can be expressed by a symmetrical, bell-shaped curve.
Normal distribution
What does the empirical rule apply to? Choose the correct option and select Submit.
Normal distributions
A probability distribution that has a bell-shape distribution with two symmetrical halves.
Normal probability distribution
If the tolerance limits are outside the specification limits, the process is considered to be what? Choose the correct option and select Submit.
Not capable
When working with natural tolerance limits, a z value of less than 3 indicates that the process is what? Choose the correct option and select Submit.
Not capable
A statement or hypothesis that states that the independent variable has no affect on the dependent variable.
Null hypothesis
The mean is computed by totaling the observation values and dividing by what? Choose the correct option and select Submit.
Number of observations
One item that occurs in an experiment.
Observation
When computing the chi-square statistic, subtract the expected frequency from what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
Observed frequency
Observation
One item that occurs in an experiment.
A prediction interval is used to compute the range Y values for what? Choose the correct option and select Submit.
One particular X values
If a hypothesis statement has a ≤ or ≥ sign in it, what is it? Choose the correct option and select Submit.
One-tailed test
The level of measurement where you organize and sort the data only is called what? Choose the correct option and select Submit.
Ordinal
If subgroup's data points are above the UCL or below the LCL, the process is __________. Choose the correct option and select Submit.
Out-of-control
The result of an experiment is a(n) _____. Choose the correct option and select Submit.
Outcome
A value that is either much larger or much smaller than the rest of the data.
Outlier
The probability of obtaining a sample observation that is extreme as or more extreme than the value observed.
P-value
What is the Excel function used to compute a permutation? Choose the correct option and select Submit.
PERMUT
An Excel function that computes the Poisson probability distribution.
POISSON
A situation in which two populations have the same random observations selected, and the difference between these observations is measured.
Paired difference
The Wilcoxon signed ranks test requires what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
Paired observations from two populations
Actual population value.
Parameter
A measurement that describes the degree a distribution is weighted either positively or negatively.
Pearson's coefficient of skewness
Divides the data into 100 equal parts (1% each).
Percentile
Items are chosen by selecting every nth item. For example, you might choose every tenth item in a lot.
Periodically
An arrangement of objects selected from a single group of objects is a what? Choose the correct option and select Submit.
Permutation
A sample statistic that is used to represent the population parameter.
Point estimate
A discrete probability distribution that involves tracking the number of times an event occurs over a period of time.
Poisson probability distribution
The entire set of items, people, or measurements that are studied.
Population
Any measurable characteristic of a population.
Population parameter
The arithmetic mean is larger than the median or mode due to one or more large values.
Positively skewed distribution
A numeric value between 0 and 1, which represents the likelihood of an event occurring.
Probability
A listing of all the possible outcomes of an experiment and the probability of each outcome occurring.
Probability distribution
Take a moment to practice probability calculation concepts in this short exercise. What is a table of all the possible outcomes of an experiment and the probability of each outcome occurring called? Choose the correct option and select Submit.
Probability distribution
When using the binomial probability distribution formula, what does the π symbol represent? Choose the correct option and select Submit.
Probability of success on a trial
The quantity of quality goods the process is capable of producing.
Process capacity
The number of successes in an experiment divided by the number of total trials.
Proportion
Take a moment to practice types of variable concepts in this short exercise. Variables that do not involve numeric characteristics are what type? Choose the correct option and select Submit.
Qualitative
To compute a p chart using MegaStat, you go to the MegaStat menu and then click on __________. Choose the correct option and select Submit.
Quality Control Process Charts
When creating control charts through MegaStat, you go to the menu MegaStat and choose __________. Choose the correct option and select Submit.
Quality Control Process charts
Variables that involve numeric characteristics are called what? Choose the correct option and select Submit.
Quantitative
Divides the data into 4 equal parts (25% each).
Quartile
When the data is divided into four even parts, it is referred to as what? Choose the correct option and select Submit.
Quartiles
When analyzing control charts, which chart should you analyze first? Choose the correct option and select Submit.
R chart
A table of numeric values that has been generated randomly from a probability distribution, such as the normal (uniform) distribution. Computers are typically used to create the values in this table.
Random number table
A sample that is chosen using random selection.
Random sample
When each item in the population has an equal chance of being selected.
Random selection
Take a moment to practice measure of dispersion concepts in this short exercise. With the measure of dispersion, what is the difference between the highest and lowest value called? Choose the correct option and select Submit.
Range
The Wilcoxon rank sum test requires the data to be what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
Ranked
Take a moment to practice levels of measurement concepts in this short exercise. The level of measurement where zero is an absence of a characteristic is called what? Choose the correct option and select Submit.
Ratio
To create an ANOVA table using Excel, choose Tools, Data Analysis, and what from the menu? Choose the correct option and select Submit.
Regression
When using Excel to do regression analysis, you go to the menu bar and choose Tools, Data Analysis, and then what? Choose the correct option and select Submit.
Regression
A technique used to express the relationship between two variables. An equation is used to express a linear relationship.
Regression analysis
Equation used to estimate the values of dependent variables.
Regression equation
If the chi-square statistic value is greater than the critical value, what should you do? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
Reject the null hypothesis
If the critical value is smaller than the computed F value, you would do what? Choose the correct option and select Submit.
Reject the null hypothesis
When p-value is less than the significance level, what should you do? Choose the correct option and select Submit.
Reject the null hypothesis
If multicollinearity exists in the correlation matrix, the typical solution is what? Choose the correct option and select Submit.
Remove a variable and rerun the experiment
What is the portion of the variance that is not explained by the independent variables called? Choose the correct option and select Submit.
Residual sum of square variation
The total variance between each observation and the overall mean (stands for sum of squares).
SS
Tells you the amount of the variance between each observation and the overall mean attributable to randomness (stands for sum of the squares error and also referred to as the error).
SSE
The formula to compute SST is SS minus what? Choose the correct option and select Submit.
SSE
Tells you the amount of variance between each observation and the overall mean attributable to the treatments (stands for sum of the squares treatment).
SST
When computing the sum of squares, you typically compute which of these last? Choose the correct option and select Submit.
SST
A portion or a subset selected from a population.
Sample
The Excel descriptive statistics feature assumes you are working with what? Choose the correct option and select Submit.
Sample
What is the total of all the sample data, divided by the number of items sampled? Choose the correct option and select Submit.
Sample mean
The difference between the actual population values of the characteristic that is tested and the sample values of that characteristic.
Sampling error
A chart used to show the relationship between bivariate data (also called a scatter plot or scatter chart).
Scatter diagram
What is a chart that displays the relationship between bivariate variables called? Choose the correct option and select Submit.
Scatter plot
The following graph illustrates _______________. Select one: a. A positive or direct relationship b. A negative or inverse relationship c. No relationship d. A distribution for a single variable
Select one: a. A positive or direct relationship
Skewness describes the ____ of a distribution. Choose the correct option and select Submit.
Shape
A nonparametric test used to hypothesize about a population median.
Sign test
The amount a distribution is weighed either positively or negatively.
Skewness
Take a moment to practice dot plot concepts in this short exercise. Dot plots work best with which of the following data sets? Choose the correct option and select Submit.
Small data sets
A nonparametric method that measures the relationship between two variables.
Spearman's rank correlation coefficient test
Take a moment to practice probability calculation concepts in this short exercise. If you want to know the probability of at least one of two or more mutually exclusive events occurring, what would you use? Choose the correct option and select Submit.
Special rule of addition
To compute the probability of two or more independent events both happening, what would you use? Choose the correct option and select Submit.
Special rule of multiplication
What is the square root of the variance? Choose the correct option and select Submit.
Standard deviation
When testing a hypothesis, what do you compare the critical value to? Choose the correct option and select Submit.
Statistic
A significance level that is so unlikely that it allows you to reject the null hypothesis.
Statistically significant
The science of gathering, organizing, analyzing, and presenting data.
Statistics
When making a decision with the F value, reject the null hypothesis when what? Choose the correct option and select Submit.
The F value is greater than the critical value.
The Wilcoxon signed ranks test ranks what? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
The absolute differences between observation values
mean deviation
The arithmetic mean of the absolute values of the deviation of each observation from the arithmetic mean.
What is a critical value? Choose the correct option and select Submit.
The cutoff point of the null hypothesis being accepted or rejected
On a dot plot chart, the horizontal axis contains which of the following? Choose the correct option and select Submit.
The data values
Range
The difference between the highest and lowest values in the data.
Deviation
The difference between two items.
population
The entire set of items, people, or measurements that are studied.
To use the geometric mean to compute a percent increase over time, you take the nth root of what? Choose the correct option and select Submit.
The last period value divided by the first period value
What is the allowable error? Choose the correct option and select Submit.
The maximum error that is permitted in the experiment
The symbol represents what? Choose the correct option and select Submit.
The mean of a treatment
What does the center line represent? Choose the correct option and select Submit.
The mean of p values
Median
The midpoint of the values after they have been arranged in order, either smallest to largest or largest to smallest.
Choose the correct option and select Submit.
The number of that subgroup's items
In the confidence interval for a population formula, what does the letter N represent? Choose the correct option and select Submit.
The number or objects in the population
If the value 0 is in the confidence interval, assume what? Choose the correct option and select Submit.
The population means are substantially the same.
One way a chart can be distorted is by changing what? Choose the correct option and select Submit.
The scale of the chart
What is one difference between a t distribution and a z distribution? Choose the correct option and select Submit.
The t distribution has more dispersion in the values.
To compute a confidence interval, you compute what value? Choose the correct option and select Submit.
The t value
Take a moment to practice uniform probability distribution concepts in this short exercise. What is a characteristic of a continuous probability distribution? Choose the correct option and select Submit.
The variables can assume an infinite number of values within a defined range
When computing the standard deviation of a probability distribution, you take the square root of what? Choose the correct option and select Submit.
The variance of the distribution
According to the empirical rule, almost all of the data is within how many deviations of the mean? Choose the correct option and select Submit.
Three
The Kruskal-Wallis H test works with how many populations? Choose the correct option and select Submit. To check your answers, select Show Me. To move on to the next question, select the Forward arrow below.
Three or more
What is the purpose of the ANOVA technique? Choose the correct option and select Submit.
To compare population means
When using Excel to sample a population, you input the population and then choose what? Choose the correct option and select Submit.
Tools option in the menu bar
A term used in ANOVA testing for the population being examined.
Treatment
A box plot shows the skewness of a distribution. Select one: True False
True
A correlation matrix can be used to assess multicollinearity between independent variables. Select one: True False
True
A correlation matrix shows individual correlation coefficients for all pairs of variables. Select one: True False
True
A dot plot is useful for showing the range of the data. Select one: True False
True
A dot plot shows the symmetry of a distribution. Select one: True False
True
A higher leeway is more desirable than a lower leeway. Choose the correct option and select Submit.
True
A p-value is a probability. Select one: True False
True
A sampling distribution of the means is a probability distribution consisting of all possible sample means of a given sample size selected from a population. Select one: True False
True
A scatter diagram is a graph that portrays the correlation between a dependent variable and an independent variable. Select one: True False
True
A value that is typical or representative of the data is referred to as a measure of central location. Select one: True False
True
According to the Empirical Rule, about 95% of the observations lie within plus and minus 2.00 standard deviations. Select one: True False
True
An economist is interested in predicting the unemployment rate based on gross domestic product. Since the economist is interested in predicting unemployment, the independent variable is gross domestic product. Select one: True False
True
An interval estimate is a range of values used to estimate a population parameter. Select one: True False
True
Assuming that the null hypothesis is true, a p-value is the probability of observing a sample value greater than and/or less than an observed sample observation. Select one: True False
True
Based on a sample of 3,000 people, the civilian unemployment rate in the United States was 5.5%. 5.5% is referred to as a statistic. Select one: True False
True
Correlation analysis is a statistical technique used to measure the strength of the relationship between two variables. Select one: True False
True
For a global test of a multiple regression equation, the F distribution is defined by the regression and residual degrees of freedom. Select one: True False
True
For a uniformly distributed random variable, x, P(x) is constant. Select one: True False
True
For an ANOVA test, rejecting the null hypothesis does not identify which treatment means differ significantly. Select one: True False
True
For any data set, Chebyshev's Theorem estimates the proportion of observations that occurs within k standard deviations of the mean, where k is greater than 1.0. Select one: True False
True
Hypothesis testing is a procedure that uses sample evidence and probability theory to decide whether to reject or fail to reject a hypothesis. Select one: True False
True
If 40 samples of size 21 were selected from a population of 22,493, we would expect the mean of the sample means and the population mean to be close but not exactly equal. Select one: True False
True
If the computed value of F is 0.99 and the F critical value is 3.89, we would not reject the null hypothesis. Select one: True False
True
If the hypothesis H0: β1= 0, is rejected, then the sample regression coefficient b1 indicates the change in the predicted value for a unit change in X1 when all other Xi variables are held constant. Select one: True False
True
If the null hypothesis states that there is no difference between the mean net income of retail stores in Chicago and New York City, then the test is two-tailed. Select one: True False
True
If we want to determine which treatment means differ, we compute a confidence interval for the difference between each pair of means. Select one: True False
True
In a multiple regression analysis, if the regression coefficient of a dummy variable is significant and has a sample value of 100, then the dummy variable's effect on the dependent variable is an increase of 100. Select one: True False
True
In the goodness-of-fit test, the chi-square distribution is used to determine how well an observed distribution of observations "fits" an expected distribution of observations. Select one: True False
True
It is often not feasible to study the entire population because it is impossible to observe all the items in the population. Select one: True False
True
One factor in determining the size of a sample is the degree of confidence selected. This is usually 0.95 or 0.99, but it may be any degree of confidence you specify. Select one: True False
True
Pearson's coefficient of skewness is a measure of a distribution's symmetry. Select one: True False
True
Percentiles divide a distribution into 100 equal parts. Select one: True False
True
Statistics are used as a basis for making decisions. Select one: True False
True
Statistics are used to report the summary results of market surveys. Select one: True False
True
Statistics is defined as a body of techniques used to facilitate the collection, organization, presentation, analysis, and interpretation of information for the purpose of making better decisions. Select one: True False
True
Stepwise regression analysis is a method that assists in selecting the most significant variables for a multiple regression equation. Select one: True False
True
The "box" in a box plot shows the interquartile range. Select one: True False
True
The 95% confidence interval states that 95% of the sample means of a specified sample size selected from a population will lie within plus and minus 1.96 standard deviations of the hypothesized population mean. Select one: True False
True
The CIA World Factbook cited these numbers for the United States:• The birthrate is 14.14 births per 1,000 population.• The average life expectancy for females is 80 years.• Approximately 290 million persons reside in the United States.Each of these numbers is referred to as a statistic. Select one: True False
True
The F distribution's curve is positively skewed. Select one: True False
True
The arithmetic mean is the sum of the quantitative observations divided by the total number of observations. Select one: True False
True
The central limit theorem allows us to use a z-statistic to compute probabilities for the sampling distribution of the sample mean. Select one: True False
True
The central limit theorem states that if the sample size, n, is sufficiently large, the sampling distribution of the means will be approximately normal, even when the population is skewed or uniform. Select one: True False
True
The chi-square distribution is positively skewed. Select one: True False
True
The chi-square test statistic used in a goodness-of-fit test has k - 1 degrees of freedom. Select one: True False
True
The coefficient of determination is the proportion of total variation in Y that is explained by X. Select one: True False
True
The least squares technique minimizes the sum of the squares of the vertical distances between the actual Y values and the predicted values of Y. Select one: True False
True
The level of significance is the probability of rejecting the null hypothesis when it is actually true. Select one: True False
True
The mean of a binomial distribution is the product of n and π. Select one: True False
True
The mean of all possible sample means is equal to the population mean. Select one: True False
True
The mode is the value of the observation that appears most frequently. Select one: True False
True
The principal difference between the interval and ratio scale is that the ratio scale has a meaningful zero point. Select one: True False
True
The shape of the chi-square distribution depends on the number of degrees of freedom. Select one: True False
True
The standard deviation is the positive square root of the variance. Select one: True False
True
The standard error of estimate measures the accuracy of a prediction. Select one: True False
True
The standard error of the mean measures the dispersion of the sampling distribution of the sample mean. Select one: True False
True
The sum of the deviations from the mean for the set of numbers 4, 9, and 5 will equal zero. Select one: True False
True
The variance inflation factor is used to select or remove independent variables to reduce the effects of multicollinearity in a multiple regression equation. Select one: True False
True
The variance of a binomial distribution is found by nπ (1 - π). Select one: True False
True
To construct a binomial distribution, it is necessary to know the total number of trials and the probability of success on each trial. Select one: True False
True
To determine the size of a sample, the standard deviation of the population must be estimated by either taking a pilot survey or by approximating it based on knowledge of the population. Select one: True False
True
To employ ANOVA, the populations being studied must be approximately normally distributed. Select one: True False
True
To employ ANOVA, the populations should have approximately equal standard deviations. Select one: True False
True
To infer something about a population, we usually take a sample from the population. Select one: True False
True
To test the null hypothesis that a set of sample data is normally distributed, we compare an expected normal distribution of the data to an observed distribution of the data. Select one: True False
True
When dependent samples are used to test for differences in the means, we compute paired differences. Select one: True False
True
When referring to the normal probability distribution, there is not just one; there is a "family" of normal probability distributions. Select one: True False
True
When using the t distribution to calculate a confidence interval, we assume that the population of interest is normal or nearly normal. Select one: True False
True
A contingency table is a cross tabulation of what? Choose the correct option and select Submit. To check your answers, select Show Me.
Two categorical variables
When converting a percentage to a decimal, how many places do you move the decimal point? Choose the correct option and select Submit.
Two places to the left
Rejecting the null hypothesis when it is actually true in the population.
Type I error
Accepting the null hypothesis when it is actually false in the population.
Type II error
If the null hypothesis is accepted and it should be rejected, what have you committed? Choose the correct option and select Submit.
Type II error
When working with a small two-sample hypothesis, what do you need to pool? Choose the correct option and select Submit.
Variance
What is a tool of analysis that graphically shows the results of an experiment? Choose the correct option and select Submit.
Venn diagram
On a box plot, what are the lines between the minimum and Q1 and the maximum and Q3 called? Choose the correct option and select Submit.
Whiskers
A nonparametric test used in paired difference experiments.
Wilcoxon signed ranks test
An experiment involves selecting a random sample of 256 middle managers for study. One item of interest is their annual income. The sample mean is computed to be $35,420, and the sample standard deviation is $2,050. What is the sample standard error of the mean? Select one: a. $128.125 b. $138.36 c. $2,050 d. $8.01
a. $128.125
Sampling error is defined as _________. Select one: a. (x¯−μ)(x¯−μ) b. σ c. σ/n d. N - n
a. (x¯−μ)(x¯−μ)
David's gasoline station offers 4 cents off per gallon if the customer pays in cash and does not use a credit card. Past evidence indicates that 40% of all customers pay in cash. During a one-hour period, 15 customers buy gasoline at this station. What is the probability that all 15 pay in cash? Select one: a. 0.0 b. 0.1 c. 0.9 d. 1.0
a. 0.0
A group of employees of Unique Services will be surveyed about a new pension plan. In-depth interviews with each employee selected in the sample will be conducted. The employees are classified as follows. Income After TaxesEventNumber of EmployeesSupervisorsA120MaintenanceB50ProductionC1,460ManagementD302SecretarialE68 What is the probability that the first person selected is a supervisor and in management? Select one: a. 0.00 b. 0.06 c. 0.15 d. 0.21
a. 0.00
A statistics professor receives an average of five e-mail messages per day from students. Assume the number of messages approximates a Poisson distribution. What is the probability that on a randomly selected day she will have no messages? Select one: a. 0.0067 b. Zero c. 0.0335 d. Impossible to have no messages
a. 0.0067
What is the area under the normal curve between z = 0.0 and z = 1.79? Select one: a. 0.4633 b. 0.0367 c. 0.9599 d. 0.0401
a. 0.4633
For a binomial distribution, the mean is 4.0 and n = 8. What is π for this distribution? Select one: a. 0.5 b. 1.00 c. 4.0 d. 0.1
a. 0.5
The Office of Student Services at a large western state university maintains information on the study habits of its full-time students. Their studies indicate that the mean amount of time undergraduate students study per week is 20 hours. The hours studied follows the normal distribution with a standard deviation of six hours. Suppose we select a random sample of 144 current students. What is the standard error of the mean? Select one: a. 0.50 b. 6.00 c. 0.25 d. 2.00
a. 0.50
The weights (in thousands of kilograms) of seven shipping containers are 9.5, 10.3, 11.0, 10.4, 10.5, 11.2, and 9.2. What is the mean deviation? Select one: a. 0.543 kg b. 0.625 kg c. 0.53 kg d. 5.50 kg
a. 0.543 kg
The weekly incomes of a large group of executives are normally distributed with a mean of $2,000 and a standard deviation of $100. What is the z-score for an income of $2,100? Select one: a. 1.00 b. 2.00 c. 1.683 d. -0.90
a. 1.00
The test scores for a class of 147 students are computed. What is the location of the test score associated with the third quartile? Select one: a. 111 b. 37 c. 74 d. 75%
a. 111
The mean weight of trucks traveling on a particular section of I-475 is not known. A state highway inspector needs an estimate of the population mean. He selects and weighs a random sample of 49 trucks and finds the mean weight is 15.8 tons. The population standard deviation is 3.8 tons. What is the 95% confidence interval for the population mean? Select one: a. 14.7 and 16.9 b. 13.2 and 17.6 c. 10.0 and 20.0 d. 16.1 and 18.1
a. 14.7 and 16.9
A study of a company's practice regarding the payment of invoices revealed that an invoice was paid an average of 20 days after it was received. The standard deviation equaled five days. Assuming that the distribution is normal, what percent of the invoices were paid within 15 days of receipt? Select one: a. 15.87% b. 37.91% c. 34.13% d. 86.74%
a. 15.87%
For the following distribution: XP(x)00.02710.18920.44130.343 What is the mean of the distribution? Select one: a. 2.1 b. 1.13 c. 0.032 d. 1.5
a. 2.1
The National Center for Health Statistics reported that of every 883 deaths in recent years, 24 resulted from an automobile accident, 182 from cancer, and 333 from heart disease. What is the probability that a particular death is due to an automobile accident? Select one: a. 24/883 or 0.027 b. 539/883 or 0.610 c. 24/333 or 0.072 d. 182/883 or 0.206
a. 24/883 or 0.027
A marketing firm is studying consumer preferences for winter fashions in four different months. From a population of women 18-21 years of age, a random sample of 100 women was selected in January. Another random sample of 100 women was selected in March. Another random sample of 100 women was selected in June. Another random sample of 100 women was selected in September. What is the number of samples? Select one: a. 4 b. 100 c. 400 d. 1
a. 4
The numbers 0 through 9 are used in code groups of four to identify an item of clothing. Code 1083 might identify a blue blouse, size medium. The code group 2031 might identify a pair of pants, size 18, and so on. Repetitions of numbers are not permitted—in other words, the same number cannot be used more than once in a total sequence. As examples, 2256, 2562, or 5559 would not be permitted. How many different code groups can be designed? Select one: a. 5,040 b. 620 c. 10,200 d. 120
a. 5,040
Mileage tests were conducted on a randomly selected sample of 100 newly developed automobile tires. The results showed that the mean tread life was 50,000 miles, with a standard deviation of 3,500 miles. What is the best estimate of the mean tread life in miles for the entire population of these tires? Select one: a. 50,000 b. 3,500 c. 500 d. 35
a. 50,000
The times (in minutes) that several underwriters took to review applications for similar insurance coverage are 50, 230, 52, and 57. What is the median length of time required to review an application? Select one: a. 54.5 b. 141.0 c. 97.25 d. 109.0
a. 54.5
A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of six hours, what is the required sample size if the error should be less than a half hour with a 95% level of confidence? Select one: a. 554 b. 130 c. 35 d. 393
a. 554
Suppose 1,600 of 2,000 registered voters sampled said they planned to vote for the Republican candidate for president. Using the 0.95 degree of confidence, what is the interval estimate for the population proportion (to the nearest 10th of a percent)? Select one: a. 78.2% to 81.8% b. 69.2% to 86.4% c. 76.5% to 83.5% d. 77.7% to 82.3%
a. 78.2% to 81.8%
The average score of 100 students taking a statistics final was 70, with a standard deviation of 7. Assuming a normal distribution, what test score separates the top 5% of the students from the lower 95% of the students? Select one: a. 81.55 b. 90.00 c. 83.72 d. 78.96
a. 81.55
At a party hall, a few friends meet each other. If each shakes hands only once with each of the others and there were a total of 36 handshakes, how many friends were at the party? Select one: a. 9 b. 12 c. 18 d. 8 e. 16
a. 9
A normally distributed random variable has _________. Select one: a. Any value between -∞ and + ∞. b. Discrete values. c. Any value between specified minimum and maximum values. d. Only two values, success and failure.
a. Any value between -∞ and + ∞.
A contingency table would be used to summarize data such as ________. Select one: a. Company employees by gender and organizational title b. Company employees by gender and age c. Company employees by compensation and age d. Company employees by compensation and years with the company
a. Company employees by gender and organizational title
Average expenditure on different items such as food, clothes, fuel comes under ____. Select one: a. Descriptive statistics b. Inferential statistics c. Applied statistics d. Business statistics e. Industrial statistics
a. Descriptive statistics
The following graph is a ____________. Select one: a. Dot plot b. Stem-and-leaf diagram c. Box plot d. Contingency table
a. Dot plot
A hypothesis regarding the weight of newborn infants at a community hospital is that the mean is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. What is the decision for a statistical significant change in average weights at birth at the 5% level of significance? Select one: a. Fail to reject the null hypothesis. b. Reject the null hypothesis and conclude the mean is higher than 6.6 lb. c. Reject the null hypothesis and conclude the mean is lower than 6.6 lb. d. Cannot calculate because the population standard deviation is unknown.
a. Fail to reject the null hypothesis.
What is a Type II error? Select one: a. Failing to reject a false null hypothesis b. Rejecting a false null hypothesis c. Accepting a false alternate hypothesis d. Rejecting a false alternate hypothesis
a. Failing to reject a false null hypothesis
If the alternate hypothesis states that µ ≠ 4,000, where is the rejection region for the hypothesis test? Select one: a. In both tails b. In the lower or left tail c. In the upper or right tail d. In the center
a. In both tails
If Gallup, Harris, and other pollsters asked people to indicate their political party affiliation as Democrat, Republican, or Independent, the data gathered would be an example of which scale of measurement? Select one: a. Nominal b. Ordinal c. Interval d. Ratio
a. Nominal
Shoe style is an example of what level of measurement? Select one: a. Nominal b. Ordinal c. Interval d. Ratio
a. Nominal
The Equal Employment Opportunity Act requires employers to classify their employees by gender and national origin. Which level of measurement is this? Select one: a. Nominal b. Ordinal c. Interval d. Ratio
a. Nominal
In a management trainee program, 80% of the trainees are female, 20% male. A total of 90% of the females attended college, while 78% of the males attended college. A management trainee is selected at random. What is the probability that the person selected is a male who did NOT attend college? Select one: a. P (male) P (did not attend college | male) b. P (did not attend college) P (male | did not attend college) c. P (male) P (did not attend college) d. P (did not attend college)
a. P (male) P (did not attend college | male)
The following graph is _______________. Select one: a. Positively skewed b. Negatively skewed c. Symmetric d. Uniformly distributed
a. Positively skewed
Which shape describes a Poisson distribution? Select one: a. Positively skewed b. Negatively skewed c. Symmetrical d. All apply
a. Positively skewed
According to the central limit theorem, _______________. Select one: a. Sample size is important when the population is not normally distributed b. Increasing sample size decreases the dispersion of the sampling distribution c. The sampling distribution of the sample means is uniform d. The sampling distribution of the sample means will be skewed
a. Sample size is important when the population is not normally distributed
The general process of gathering, organizing, summarizing, analyzing, and interpreting data is called ____________. Select one: a. Statistics b. Descriptive statistics c. Inferential statistics d. Levels of measurement
a. Statistics
Which of the following is an example of a continuous variable? Select one: a. Tons of concrete to complete a parking garage b. Number of students in a statistics class c. Zip codes of shoppers d. Rankings of baseball teams in a league
a. Tons of concrete to complete a parking garage
In a contingency table, we describe the relationship between ________. Select one: a. Two variables measured at the ordinal or nominal level b. Two variables, one measured as an ordinal variable and the other as a ratio variable c. Two variables measured at the interval or ratio level d. A variable measure on the interval or ratio level and time
a. Two variables measured at the ordinal or nominal level
A manufacturer wants to increase the shelf life of a line of cake mixes. Past records indicate that the average shelf life of the mix is 216 days. After a revised mix has been developed, a sample of nine boxes of cake mix gave these shelf lives (in days): 215, 217, 218, 219, 216, 217, 217, 218, and 218. Using α = 0.025, has the shelf life of the cake mix increased? Select one: a. Yes, because computed t is greater than the critical value. b. Yes, because computed t is less than the critical value. c. No, because computed t lies in the region of acceptance. d. No, because 217.24 is quite close to 216.
a. Yes, because computed t is greater than the critical value.
The mean length of a candy bar is 43 millimeters. There is concern that the settings of the machine cutting the bars have changed. Test the claim at the 0.02 level that there has been no change in the mean length. The alternate hypothesis is that there has been a change. Twelve bars (n = 12) were selected at random and their lengths recorded. The lengths are (in millimeters) 42, 39, 42, 45, 43, 40, 39, 41, 40, 42, 43, and 42. The mean of the sample is 41.5 and the standard deviation is 1.784. Computed t = -2.913. Has there been a statistically significant change in the mean length of the bars? Select one: a. Yes, because the computed t lies in the rejection region. b. No, because the information given is not complete. c. No, because the computed t lies in the area to the right of -2.718. d. Yes, because 43 is greater than 41.5.
a. Yes, because the computed t lies in the rejection region.
For a hypothesis test comparing two population means, the combined degrees of freedom are 24. Which of the following statements about the two sample sizes is NOT true? Assume the population standard deviations are equal. Select one: a. n1 = 11; n2 = 13 b. n1 = 12; n2 = 14 c. n1 = 13; n2 = 13 d. n1 = 10; n2 = 16
a. n1 = 11; n2 = 13
A recent study focused on the number of times men and women send a Twitter message in a day. The sample information is summarized below. Sample SizeSample MeanPopulation Standard DeviationMen25235Women302810 At the .01 significance level, is there a difference in the mean number of times men and women send a Twitter message in a day? What is the test statistic for this hypothesis? Select one: a. z-statistic b. t-statistic c. p-statistic d. df-statistic
a. z-statistic
The distribution of the annual incomes of a group of middle management employees approximated a normal distribution with a mean of $37,200 and a standard deviation of $800. About 68% of the incomes lie between what two incomes? Select one: a. $30,000 and $40,000 b. $36,400 and $38,000 c. $34,800 and $39,600 d. $35,600 and $38,800
b. $36,400 and $38,000
A sample of the paramedical fees charged by clinics revealed these amounts: $55, $49, $50, $45, $52, and $55. What is the median charge? Select one: a. $47.50 b. $51.00 c. $52.00 d. $55.00
b. $51.00
For a hypothesis comparing two population means, H0: μ1 ≤ μ2, what is the critical value for a one-tailed hypothesis test, using a 5% significance level, with both sample sizes equal to 13? Assume the population standard deviations are equal. Select one: a. +1.401 b. +1.711 c. +2.060 d. +2.064
b. +1.711
What is the possible range of values for Pearson's coefficient of skewness? Select one: a. -1 and +1 b. -3 and +3 c. 0% and 100% d. Unlimited values
b. -3 and +3
The wildlife department has been feeding a special food to rainbow trout fingerlings in a pond. Based on a large number of observations, the distribution of trout weights is normally distributed with a mean of 402.7 grams and a standard deviation 8.8 grams. What is the probability that the mean weight for a sample of 40 trout exceeds 405.5 grams? Select one: a. 0.3782 b. 0.0222 c. 1.0 d. 0.5
b. 0.0222
Chances are 50-50 that a newborn baby will be a girl. For families with five children, what is the probability that all the children are girls? Select one: a. 0.900 b. 0.031 c. 0.001 d. 0.250
b. 0.031
Customers of the Key Refining Company charge an average of $70 per month. The distribution of amounts charged is approximately normal, with a standard deviation of $10. What is the probability of selecting a credit card customer at random and finding the customer charged between $70 and $83? Select one: a. 0.1962 b. 0.4032 c. 0.3413 d. 0.4750
b. 0.4032
The following is a binomial probability distribution with n = 3 and π = 0.20. XP(x)00.02710.18920.44130.343 The mean of the distribution is _______. Select one: a. 1.50 b. 0.60 c. 0.25 d. 0.00
b. 0.60
A rug manufacturer has decided to use seven compatible colors in her rugs. However, in weaving a rug, only five spindles can be used. In advertising, the rug manufacturer wants to indicate the number of different color groupings for sale. How many color groupings using the seven colors taken five at a time are there? (This assumes that five different colors will go into each rug—in other words, there are no repetitions of color.) Select one: a. 7 b. 21 c. 840 d. 42
b. 21
A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of three hours, what is the required sample size if the error should be less than a half hour with a 99% level of confidence? Select one: a. 196 b. 239 c. 15 d. 16
b. 239
A sales representative calls on four hospitals in Westchester County. It is immaterial what order he calls on them. How many different arrangements can be made with the 4? Select one: a. 4 b. 24 c. 120 d. 37
b. 24
Using the following statistics to describe a distribution of data, what is the interquartile range?Minimum = 10Q1 = 25Median = 50Q3 = 75Maximum = 95 Select one: a. 85 b. 50 c. 15 d. 20
b. 50
A dot plot is best applied for a data set with __________. Select one: a. 1,000 observations b. 50 observations c. More than one variable d. One mode
b. 50 observations
Over the last six months, the following numbers of absences have been reported: 6, 0, 10, 14, 8, and 0. What is the median number of monthly absences? Select one: a. 6 b. 7 c. 8 d. 3
b. 7
You have the assignment of designing color codes for different parts. Three colors are used to code on each part. Once a combination of three colors is used—such as green, yellow, and red—these three colors cannot be rearranged to use as a code for another part. If there are 35 combinations, how many colors were available? Select one: a. 5 b. 7 c. 9 d. 11
b. 7
A hypothesis regarding the weight of newborn infants at a community hospital is that the mean is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. What is the sample mean? Select one: a. 6.6 b. 7.6 c. 1.177 d. 2.447
b. 7.6
An analysis of the grades on the first test in History 101 revealed that they approximate a normal curve with a mean of 75 and a standard deviation of 8. The instructor wants to award the grade of A to the upper 10% of the test grades. To the nearest percent, what is the dividing point between an A and a B grade? Select one: a. 80 b. 85 c. 90 d. 95
b. 85
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are presented next. Process AProcess BSample mean2.03.0Standard deviation1.00.5Sample size1214 The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. This example is what type of test? Select one: a. A one-sample test of means b. A two-sample test of means c. A paired t-test d. A test of proportions
b. A two-sample test of means
For a population that is not normally distributed, the distribution of the sample means will ________. Select one: a. Be negatively skewed b. Approach a normal distribution c. Be positively skewed d. Take the same shape as the population
b. Approach a normal distribution
If a student places in the 99th percentile on an exam, she performed better than 99% of all students who completed the exam. Her performance is similar to a statement based on a __________. Select one: a. Frequency table b. Cumulative frequency distribution c. Histogram d. Pie chart
b. Cumulative frequency distribution
Which approach to probability is exemplified by the following formula? Probability of an Event=Number of times event occurred in the pastTotal number of observations Select one: a. Classical approach b. Empirical approach c. Subjective approach d. None Apply
b. Empirical approach
The average cost of tuition and room and board at small private liberal arts colleges is reported to be $8,500 per term, but a financial administrator believes that the average cost is higher. A study conducted using 350 small liberal arts colleges showed that the average cost per term is $8,745. The population standard deviation is $1,200. Let α = 0.05. Based on the computed test statistic or p-value, what is our decision about the average cost? Select one: a. Equal to $8,500 b. Greater than $8,500 c. Less than $8,500 d. Not equal to $8,500
b. Greater than $8,500
When testing the hypothesized equality of two population means, the implied null hypothesis is ____________. Select one: a. H0: µ1 = 0 b. H0: µ1 - µ2 = 0 c. H0: µ2 = 0 d. H0: µ1 - µ2 ≠ 0
b. H0: µ1 - µ2 = 0
The mean annual incomes of certified welders are normally distributed with the mean of $50,000 and a standard deviation of $2,000. The ship building association wishes to find out whether their welders earn more or less than $50,000 annually. The alternate hypothesis is that the mean is not $50,000. Which of the following is the alternate hypothesis? Select one: a. H1: π ≠ $50,000 b. H1: µ ≠ $50,000 c. H1: µ < $50,000 d. H1: µ = $50,000
b. H1: µ ≠ $50,000
A hypothesis regarding the weight of newborn infants at a community hospital is that the mean is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds. What is the alternate hypothesis? Select one: a. H1: µ = 6.6 b. H1: µ ≠ 6.6 c. H1: µ ≥ 6.6 d. H1: µ > 7.6
b. H1: µ ≠ 6.6
As the size of the sample increases, what happens to the shape of the distribution of sample means? Select one: a. It cannot be predicted in advance. b. It approaches a normal distribution. c. It is positively skewed. d. It is negatively skewed.
b. It approaches a normal distribution.
In a distribution, the second quartile corresponds with the __________. Select one: a. Mean b. Median c. Mode d. Variance
b. Median
What is the lowest level of measurement that a median can be computed? Select one: a. Nominal b. Ordinal c. Interval d. Ratio
b. Ordinal
What does the complement rule state? Select one: a. P(A) = P(A) - P(B) b. P(A) = 1 - P(not A) c. P(A) = P(A) × P(B) d. P(A) = P(A)X + P(B)
b. P(A) = 1 - P(not A)
A portion or part of a population is called a Select one: a. Random survey b. Sample c. Tally d. Frequency distribution
b. Sample
If the coefficient of skewness is equal to zero, the shape of the distribution is __________. Select one: a. Negatively skewed b. Symmetric c. Positively skewed d. Unknown
b. Symmetric
What does the interquartile range describe? Select one: a. The range of the lower 50% of the observations b. The range of the middle 50% of the observations c. The range of the upper 50% of the observations d. The ranges of the lower 25% and the upper 25% of the observations
b. The range of the middle 50% of the observations
A box plot shows ___________. Select one: a. The mean and variance b. The relative symmetry of a distribution for a set of data c. The 10th and 90th percentiles of a distribution d. The deciles of a distribution
b. The relative symmetry of a distribution for a set of data
A survey of households in a small town showed that in 500 of 1,200 sampled households, at least one member attended a town meeting during the year. Using the 95% level of confidence, what is the confidence interval for the proportion of households represented at a town meeting? Select one: a. [0.417, 0.427] b. [0.389, 0.445] c. [0.400, 0.417] d. [0.417, 0.445]
b. [0.389, 0.445]
Based on the Nielsen ratings, the local CBS affiliate claims its 11 p.m. newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening news on this local CBS station. What is the critical value if the level of significance is 0.10? Select one: a. -1.282 b. ±1.645 c. -2.576 d. +2.576
b. ±1.645
The mean of all the sample means is _______. Select one: a. x¯x¯ b. µ c. σ d. α
b. µ
The net weights (in grams) of a sample of bottles filled by a machine manufactured by Edne, and the net weights of a sample filled by a similar machine manufactured by Orno, Inc., are: Edne876975 Orno107119121498 Testing the claim at the 0.05 level that the mean weight of the bottles filled by the Orno machine is greater than the mean weight of the bottles filled by the Edne machine, what is the critical value? Assume equal standard deviations for both samples. Select one: a. +2.179 b. +2.145 c. +1.782 d. +1.761
c. +1.782
A national manufacturer of ball bearings is experimenting with two different processes for producing precision ball bearings. It is important that the diameters be as close as possible to an industry standard. The output from each process is sampled and the average error from the industry standard is measured in millimeters. The results are presented next. Process AProcess BSample mean2.03.0Standard deviation1.00.5Sample size1214 The researcher is interested in determining whether there is evidence that the two processes yield different average errors. The population standard deviations are unknown but are assumed equal. What is the computed value of t? Select one: a. +2.797 b. -1.000 c. -3.299 d. 0.5938
c. -3.299
The weight of cans of fruit is normally distributed with a mean of 1,000 grams and a standard deviation of 50 grams. What percent of the cans weigh 860 grams or less? Select one: a. 0.0100 b. 0.8400 c. 0.0026 d. 0.0001
c. 0.0026
A group of employees of Unique Services will be surveyed about a new pension plan. In-depth interviews with each employee selected in the sample will be conducted. The employees are classified as follows. Income After TaxesEventNumber of EmployeesSupervisorsA120MaintenanceB50ProductionC1,460ManagementD302SecretarialE68 What is the probability that the first person selected is classified as a maintenance employee? Select one: a. 0.20 b. 0.50 c. 0.025 d. 1.00
c. 0.025
A group of employees of Unique Services will be surveyed about a new pension plan. In-depth interviews with each employee selected in the sample will be conducted. The employees are classified as follows. Income After TaxesEventNumber of EmployeesSupervisorsA120MaintenanceB50ProductionC1,460ManagementD302SecretarialE68 What is the probability that the first person selected is either in maintenance or in secretarial? Select one: a. 0.200 b. 0.015 c. 0.059 d. 0.001
c. 0.059
David's gasoline station offers 4 cents off per gallon if the customer pays in cash and does not use a credit card. Past evidence indicates that 40% of all customers pay in cash. During a one-hour period, 15 customers buy gasoline at this station. What is the probability that more than 8 and less than 12 customers pay in cash? Select one: a. 0.210 b. 0.212 c. 0.092 d. 0.562
c. 0.092
What is the area under the normal curve between z = -1.0 and z = -2.0? Select one: a. 0.0228 b. 0.3413 c. 0.1359 d. 0.4772
c. 0.1359
Each salesperson in a large department store chain is rated on their sales ability and their potential for advancement. The data for the 500 sampled salespeople are summarized in the following table. Potential for Advancement FairGoodExcellentSales AbilityBelow Average 16 12 22 Average4 5 60 45 Above Average9 3 72 135 What is the probability that a salesperson selected at random has above average sales ability and has excellent potential for advancement? Select one: a. 0.20 b. 0.50 c. 0.27 d. 0.75
c. 0.27
A total of 60% of the customers of a fast food chain order a hamburger, French fries, and a drink. If a random sample of 15 cash register receipts is selected, what is the probability that 10 or more will show that the above three food items were ordered? Select one: a. 1.000 b. 0.186 c. 0.403 d. 0.000
c. 0.403
Judging from recent experience, 5% of the computer keyboards produced by an automatic, high-speed machine are defective. If six keyboards are randomly selected, what is the probability that none of the keyboards are defective? Select one: a. 0.001 b. 0.167 c. 0.735 d. 0.500
c. 0.735
A tennis match requires that a player win three of five sets to win the match. If a player wins the first two sets, what is the probability that the player wins the match, assuming that each player is equally likely to win each set? Select one: a. 0.500 b. 0.125 c. 0.875 d. 0.000
c. 0.875
Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes and the standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What is the standard error of the mean? Select one: a. 14 minutes b. 140 minutes c. 1.4 minutes d. 90 minutes
c. 1.4 minutes
What does 6!2!4!3!6!2!4!3! equal? Select one: a. 640 b. 36 c. 10 d. 120
c. 10
A multiple choice quiz contains 5 questions. Each question has answer choices labeled a, b, c, and d. How many different ways can a student answer the five questions? Select one: a. 20 b. 625 c. 1024 d. 120 e. 5
c. 1024
A developer of a new subdivision wants to build homes that are all different. There are three different interior plans that can be combined with any of five different home exteriors. How many different homes can be built? Select one: a. 8 b. 10 c. 15 d. 30
c. 15
A postman wants to post the letters in letterbox. In how many ways can 5 letters be posted in 7 letterboxes? Assume each box can have only one letter. Select one: a. 12 b. 120 c. 2520 d. 35 e. 5040
c. 2520
A random sample of packets of cereals is collected to check whether the machine is working accurately. The goal is to have 500 g of cereal in each packet. Mean and variance obtained for the sample were 499 g and 9 g respectively. The point estimate of population standard deviation is______. Select one: a. 9 g b. 4.5 g c. 3 g d. 81 g e. 18 g
c. 3 g
The results of a mathematics placement exam at two different campuses of Mercy College follow: CampusSample SizeMeanPopulation Std. Deviation13303382310317 What is the compound value of the test statistic? Select one: a. 9.30 b. 2.60 c. 3.37 d. 3.40
c. 3.37
How many permutations of the three letters C, D, and E are possible? Select one: a. 3 b. 0 c. 6 d. 8
c. 6
A random sample of 85 supervisors revealed that they worked an average of 6.5 years before being promoted. The population standard deviation was 1.7 years. Using the 0.95 degree of confidence, what is the confidence interval for the population mean? Select one: a. 6.99 and 7.99 b. 4.15 and 7.15 c. 6.14 and 6.86 d. 6.49 and 7.49
c. 6.14 and 6.86
For the normal distribution, the mean plus and minus two standard deviations will include about what percent of the observations? Select one: a. 50% b. 99.7% c. 95% d. 68%
c. 95%
Twenty randomly selected statistics students were given 15 multiple-choice questions and 15 open-ended questions, all on the same material. The professor was interested in determining if students scored higher on the multiple-choice questions. This experiment is an example of ________________. Select one: a. A one-sample test of means b. A two-sample test of means c. A paired t-test d. A test of proportions
c. A paired t-test
Accounting procedures allow a business to evaluate its inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, does the LIFO method result in a lower cost of inventory than the FIFO method? ProductFIFO(F)LIFO(L)12252212119100310011342122005248245 This example is what type of test? Select one: a. A one-sample test of means. b. A two-sample test of means. c. A paired t-test. d. A test of proportions.
c. A paired t-test.
What are the critical values for a two-tailed test with a 0.01 level of significance when n is large and the population standard deviation is known? Select one: a. Above 1.960 and below -1.960 b. Above 1.645 and below -1.645 c. Above 2.576 and below -2.576 d. Above 1.000 and below -1.000
c. Above 2.576 and below -2.576
David's gasoline station offers 4 cents off per gallon if the customer pays in cash and does not use a credit card. Past evidence indicates that 40% of all customers pay in cash. During a one-hour period, 15 customers buy gasoline at this station. This situation is an example of what type of discrete probability distribution? Select one: a. Continuous probability distribution b. Poisson probability distribution c. Binomial probability distribution d. Hypergeometric probability distribution
c. Binomial probability distribution
The range of the coefficient of skewness is ____________. Select one: a. Values greater than or equal to zero or always positive b. Values less than or equal to zero or always negative c. Both positive and negative values d. Values between -1 and +1
c. Both positive and negative values
The following graph is a Select one: a. Dot plot b. Stem-and-leaf display c. Box plot d. Contingency table
c. Box plot
The interquartile range is graphically presented in a ___________. Select one: a. Dot plot b. Stem-and-leaf display c. Box plot d. Contingency table
c. Box plot
A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized next. Sample SizeSample MeanPopulation Standard DeviationMen 25235Women 302810 At the .01 significance level, is there a difference in the mean number of times men and women send a Twitter message in a day? Based on the p-value, what is your conclusion? Select one: a. Reject the null hypothesis and conclude the means are different. b. Reject the null hypothesis and conclude the means are the same. c. Fail to reject the null hypothesis. d. Fail to reject the null hypothesis and conclude the means are different.
c. Fail to reject the null hypothesis.
The average cost of tuition and room and board at a small private liberal arts college is reported to be $8,500 per term, but a financial administrator believes that the average cost is higher. A study conducted using 350 small liberal arts colleges showed that the average cost per term is $8,745. The population standard deviation is $1,200. Let α = 0.05. What are the null and alternative hypotheses for this study? Select one: a. H0: µ ≤ $9,000; H1: µ > $9,000 b. H0: µ ≥ $9,000; H1: µ < $9,000 c. H0: µ ≤ $8,500; H1: µ > $8,500 d. H0: µ ≥ $8,500; H1: µ < $8,500
c. H0: µ ≤ $8,500; H1: µ > $8,500
The reported unemployment is 5.5% of the population. What measurement scale is used to measure unemployment? Select one: a. Nominal b. Ordinal c. Interval or ratio d. Descriptive
c. Interval or ratio
The size of the sampling error is ________. Select one: a. Directly related to the sample size—in other words, the larger the sample size, the larger the sampling error b. Directly related to the population mean—in other words, the larger the mean, the larger the sampling error c. Inversely related to the sample size—in other words, the larger the sample size, the smaller the sampling error d. Inversely related to the population standard deviation—in other words, the smaller the standard deviation, the larger the sampling error
c. Inversely related to the sample size—in other words, the larger the sample size, the smaller the sampling error
Knowing the population standard deviation, a 95% confidence interval infers that the population mean ___________. Select one: a. Is between 0 and 100% b. Is within ±1.96 standard deviations of the sample mean c. Is within ±1.96 standard errors of the sample mean d. Is too large
c. Is within ±1.96 standard errors of the sample mean
To study the population of consumer perceptions of new technology, sampling of the population is preferred over surveying the population because _________. Select one: a. Sampling is more accurate b. We can compute z-scores c. It is quicker d. Sampling methods are simple
c. It is quicker
For a positively skewed distribution, Select one: a. Mean = Median b. Mean < Median c. Mean > Median
c. Mean > Median
Which measures of central location are not affected by extremely small or extremely large values? Select one: a. Mean and median b. Mean and mode c. Mode and median d. Standard deviation and mean
c. Mode and median
There is a single peak in ___________ distribution, and the observations extend further to the left. Select one: a. Positively skewed b. Symmetric c. Negatively skewed d. Uniform
c. Negatively skewed
The following graph is______ Select one: a. Positively skewed. b. Symmetric. c. Negatively skewed. d. Unknown.
c. Negatively skewed.
Collection of_______ is called Statistics. Select one: a. Methods b. Sample data c. Numerical information d. Population data e. Cleaned data
c. Numerical information
In a management trainee program, 80% of the trainees are female, 20% male. A total of 90% of the females attended college, while 78% of the males attended college. A management trainee is selected at random. What is the probability that the person selected is a female who did attend college? Select one: a. P (female) P (did not attend college | female) b. P (did attend college) P (female | did not attend college) c. P (female) P (did attend college | female) d. P (did attend college)
c. P (female) P (did attend college | female)
Pearson coefficient of skewness for symmetric distribution is_____ Select one: a. Sk = -3 b. Sk = 3 c. Sk = 0 d. Sk = 1 e. Sk = -1
c. Sk = 0
The quartiles for the duration of calls (in minutes) made by an operator in a day are: Q1 = 13, Q2 = 19 and Q3 = 25 Using this information, the shape of the distribution is _______ Select one: a. Positively skewed. b. Unknown. c. Symmetric. d. Negatively skewed.
c. Symmetric.
According to the central limit theorem, ____________. Select one: a. The population mean and the mean of all sample means are equal b. Increasing sample size decreases the dispersion of the sampling distribution c. The sampling distribution of the sample means is approximately normally distributed d. The sampling distribution of the sample means will be skewed
c. The sampling distribution of the sample means is approximately normally distributed
Which condition must be met to conduct a test for the difference in two sample means using a z-statistic? Select one: a. The data must be at least of nominal scale. b. The populations must be normal. c. The two population standard deviations must be known. d. The samples are dependent.
c. The two population standard deviations must be known.
In a scatter diagram, we describe the relationship between __________. Select one: a. Two variables measured at the ordinal level b. Two variables, one measured as an ordinal variable and the other as a ratio variable c. Two variables measured at the interval or ratio level d. A variable measure on the interval or ratio level and time
c. Two variables measured at the interval or ratio level
When a confidence interval for a population mean is constructed from sample data, __________. Select one: a. We can conclude that the population mean is in the interval b. We can conclude that the population mean is not in the interval c. We can conclude, for an infinite number of samples and corresponding confidence intervals, that the population mean is in a stated percentage of the intervals d. We cannot make any inferences
c. We can conclude, for an infinite number of samples and corresponding confidence intervals, that the population mean is in a stated percentage of the intervals
Which of the following is the standard error of the mean? Select one: a. σ b. x/n c. σn√σn d. s
c. σn√σn
A local retail company wants to estimate the mean amount spent by customers. Their store's budget limits the number of surveys to 225. What is their maximum error of the estimated mean amount spent for a 99% level of confidence and an estimated standard deviation of $10.00? Select one: a. $10 b. $1.00 c. 1% d. $1.72
d. $1.72
The following are the weekly amounts of welfare payments made by the federal government to a sample of six families: $139, $136, $130, $136, $147, and $136. What is the range? Select one: a. $0 b. $14 c. $52 d. $17
d. $17
A stockbroker placed the following order for a customer:• 50 shares of Kaiser Aluminum at $104 a share• 100 shares of GTE at $25.25 a share• 20 shares of Boston Edison at $9.125 a shareWhat is the weighted arithmetic mean price per share? Select one: a. $25.25 b. $79.75 c. $103.50 d. $46.51
d. $46.51
A statistics professor receives an average of five e-mail messages per day from students. Assume the number of messages approximates a Poisson distribution. What is the probability that on a randomly selected day she will have two messages? Select one: a. 0.0067 b. 0.0014 c. 0.4200 d. 0.0842
d. 0.0842
A manufacturer of headache medicine claims it is 70% effective within a few minutes. That is, out of every 100 users, 70 get relief within a few minutes. A group of 12 patients are given the medicine. If the claim is true, what is the probability that eight have relief within a few minutes? Select one: a. 0.001 b. 0.168 c. 0.667 d. 0.231
d. 0.231
The Intelligence Quotient (IQ) test scores for adults are normally distributed with a mean of 100 and a standard deviation of 15. What is the probability we could select a sample of 50 adults and find that the mean of this sample is between 98 and 103? Select one: a. 0.3264 b. 0.9428 c. 0.4702 d. 0.7471
d. 0.7471
A board of directors consists of eight men and four women. A four-member search committee is randomly chosen to recommend a new company president. What is the probability that all four members of the search committee will be women? Select one: a. 1/120 or 0.00083 b. 1/16 or 0.0625 c. ⅛ or 0.125 d. 1/495 or 0.002
d. 1/495 or 0.002
Percentiles divide a distribution into _____________. Select one: a. 2 equal parts b. 4 equal parts c. 10 equal parts d. 100 equal parts
d. 100 equal parts
An accelerated life test on a large number of type-D alkaline batteries revealed that the mean life for a particular use before they failed is 19.0 hours. The distribution of the lives approximated a normal distribution. The standard deviation of the distribution was 1.2 hours. About 95.44% of the batteries failed between what two values? Select one: a. 8.9 and 18.9 b. 12.2 and 14.2 c. 14.1 and 22.1 d. 16.6 and 21.4
d. 16.6 and 21.4
The weights of a sample of crates ready for shipment to Moscow, Russia are (in kilograms): 103, 97, 101, 106, and 103. What is the mean deviation? Select one: a. 0 kg b. 6.9 kg c. 102.0 kg d. 2.4 kg
d. 2.4 kg
A recent study focused on the number of times men and women send a Twitter message in a day. The information is summarized next. Sample SizeSample MeanPopulation Standard DeviationMen 25235Women 302810 At the .01 significance level, is there a difference in the mean number of times men and women send a Twitter message in a day? What is the value of the test statistic for this hypothesis test? Select one: a. 2.668 b. 2.672 c. 2.58 d. 2.40
d. 2.40
A lamp manufacturer designed five lamp bases and four lampshades that could be used together. How many different arrangements of base and shade can be offered? Select one: a. 5 b. 10 c. 15 d. 20
d. 20
What is the median of 26, 30, 24, 32, 32, 31, 27, and 29? Select one: a. 32 b. 29 c. 30 d. 29.5
d. 29.5
A supplier delivers an order for 20 electric toothbrushes to a store. By accident, three of the electric toothbrushes are defective. What is the probability that the first two electric toothbrushes sold will be returned because they are defective? Select one: a. 3/20 or 0.15 b. 3/17 or 0.176 c. ¼ or 0.25 d. 3/190 or 0.01579
d. 3/190 or 0.01579
A national manufacturer of unattached garages discovered that the distribution of the time for two construction workers to erect the Red Barn model is normally distributed with a mean of 32 hours and a standard deviation of 2 hours. What percent of the garages take between 32 and 34 hours to erect? Select one: a. 16.29% b. 76.71% c. 3.14% d. 34.13%
d. 34.13%
A large manufacturing firm tests job applicants. Test scores are normally distributed with a mean of 500 and a standard deviation of 50. Management is considering placing a new hire in an upper-level management position if the person scores in the upper sixth percent of the distribution. What is the lowest score a new hire must earn to qualify for a responsible position? Select one: a. 50 b. 625 c. 460 d. 578
d. 578
The standard normal probability distribution is unique because it has _________. Select one: a. A mean of 1 and any standard deviation b. Any mean and a standard deviation of 1 c. A mean of 0 and any standard deviation d. A mean of 0 and a standard deviation of 1
d. A mean of 0 and a standard deviation of 1
A dot plot is best applied when _____________________. Select one: a. The mean, median, and mode are equal b. The general shape of a distribution is symmetric c. The relationship between two variables is summarized d. A single variable is summarized
d. A single variable is summarized
The mean score of a college entrance test is 500; the standard deviation is 75. The scores are normally distributed. What percent of the students scored below 320? Select one: a. About 50.82% b. About 34.13% c. About 7.86% d. About 0.82%
d. About 0.82%
Which of the following measures of dispersion are based on deviations from the mean? Select one: a. Variance b. Standard deviation c. Mean deviation d. All apply
d. All apply
What type of variable is "pounds of popcorn" served at a movie theater? Select one: a. Interval b. Ratio c. Discrete d. Continuous
d. Continuous
For a given population, the mean of all the sample means (x̄) of sample size n, and the mean of all (N) population observations (X) are _______. Select one: a. Equal to (x̄) b. Not equal c. Equal to ( x̄ - µ ) d. Equal to the population mean µ
d. Equal to the population mean µ
Accounting procedures allow a business to evaluate its inventory costs based on two methods: LIFO (Last In First Out) or FIFO (First In First Out). A manufacturer evaluated its finished goods inventory (in $000s) for five products with the LIFO and FIFO methods. To analyze the difference, they computed (FIFO - LIFO) for each product. Based on the following results, does the LIFO method result in a lower cost of inventory than the FIFO method? ProductFIFO(F)LIFO(L)12252212119100310011342122005248245 What is the decision at the 5% level of significance? Select one: a. Fail to reject the null hypothesis and conclude LIFO is more effective. b. Reject the null hypothesis and conclude LIFO is more effective. c. Reject the alternate hypothesis and conclude LIFO is more effective. d. Fail to reject the null hypothesis.
d. Fail to reject the null hypothesis.
It is claimed that in a bushel of peaches, less than 10% are defective. A sample of 400 peaches is examined and 50 are found to be defective. If α = 0.025, what will be the decision? Select one: a. Accept the null. b. Reject the null and conclude the defects are not greater than 10%. c. Reject the null and conclude the defects are greater than 10%. d. Fail to reject the null.
d. Fail to reject the null.
The results of a mathematics placement exam at two different campuses of Mercy College follow: CampusSample SizeMeanPopulation Std. Deviation13303382310317 What is the null hypothesis if we want to test the hypothesis that the mean score on Campus 1 is higher than on Campus 2? Select one: a. H0: µ1 = 0 b. H0: µ2 = 0 c. H0: µ1 = µ2 d. H0: µ1 ≤ µ2
d. H0: µ1 ≤ µ2
A survey includes a question regarding marital status that has the following responses: single, married, divorced, separated, or widowed. What is the scale of measurement for this question? Select one: a. Ratio b. Interval c. Ordinal d. Nominal
d. Nominal
A sample standard deviation is the best point estimate of the ___________. Select one: a. Population range b. Population skewness c. Population mode d. Population standard deviation
d. Population standard deviation
The Nielsen Ratings break down the number of people watching a particular television show by age. What level of measurement is age? Select one: a. Nominal b. Ordinal c. Interval d. Ratio
d. Ratio
What is another name for the alternate hypothesis? Select one: a. Null hypothesis b. Hypothesis of no difference c. Rejected hypothesis d. Research hypothesis
d. Research hypothesis
If the variance of the "number of daily parking tickets issued is 100, the standard deviation is defined as the _____________. Select one: a. "Number of daily parking tickets" b. "Number of daily parking tickets" squared. c. Absolute value of the variance of the "number of daily parking tickets" d. Square root of the variance of the "number of daily parking tickets"
d. Square root of the variance of the "number of daily parking tickets"
Suppose we select every fifth invoice in a file. What type of sampling is this? Select one: a. Random b. Cluster c. Stratified d. Systematic
d. Systematic
Which of the following is NOT a characteristic of a binomial probability distribution? Select one: a. Each outcome is mutually exclusive. b. Each trial is independent. c. The probability of success remains constant from trial to trial. d. The number of trials is limited to two.
d. The number of trials is limited to two.
To conduct a test of hypothesis with a small sample, we make an assumption that __________. Select one: a. A larger computed value of t will be needed to reject the null hypothesis b. The region of acceptance will be wider than for large samples c. The confidence interval will be wider than for large samples d. The population is normally distributed
d. The population is normally distributed
Bones Brothers & Associates prepare individual tax returns. Over prior years, Bones Brothers has maintained careful records regarding the time to prepare a return. The mean time to prepare a return is 90 minutes and the standard deviation of this distribution is 14 minutes. Suppose 100 returns from this year are selected and analyzed regarding the preparation time. What assumptions do you need to make about the shape of the population distribution of all possible tax preparation times to make inferences about the mean time to complete a tax form? Select one: a. The population distribution is skewed to the right. b. The population distribution is skewed to the left. c. The population distribution is normal. d. The shape of the population distribution does not matter.
d. The shape of the population distribution does not matter.
If 95% and 98% confidence intervals were developed to estimate the true cost of an MP3 player with a known population standard deviation, what differences would they have? Select one: a. The standard errors would be different. b. The point estimates of the population mean would be different. c. The sample sizes would be different. d. The z statistics would be different.
d. The z statistics would be different.
When using Student's t to compute an interval estimate, ___________. Select one: a. We assume that the samples are collected from populations that are uniformly distributed b. We estimate the population mean based on the sample mean c. We use the z distribution d. We assume that the samples are collected from normally distributed populations
d. We assume that the samples are collected from normally distributed populations
A student wanted to construct a 95% confidence interval for the mean age of students in her statistics class. She randomly selected nine students. Their mean age was 19.1 years, with a sample standard deviation of 1.5 years. What is the 95% confidence interval for the population mean? Select one: a. [0.97, 3.27] b. [15.64, 22.56] c. [17.97, 20.23] d. [17.95, 20.25]
d. [17.95, 20.25]
a company is researching the effectiveness of a new website design to decrease the time to access a website. five website users were randomly selected, and their times (in seconds) to access the website with the old and new designs were recorded. to compare the times, they computed (new website design time - old website design time). the results follow. user old website design new website design a 30 25 b 45 30 c 25 20 d 32 30 e 28 27 what is the null hypothesis? select one: a. h0: μd = 0 b. h0: μd ≠ 0 c. h0: μd ≤ 0 d. h0: μd ≥ 0
d. h0: μd ≥ 0
A letter used to indicate the number of treatments in an experiment.
k
What do you divide by when computing a sample variance? Choose the correct option and select Submit.
n-1
When working with a small sample size, what should you use? Choose the correct option and select Submit.
t statistic
If the population standard deviation is known, what should you use? Choose the correct option and select Submit.
z test
To convert a normal distribution to a standard normal distribution, what should you use? Choose the correct option and select Submit.
z values
What symbol represents the population mean? Choose the correct option and select Submit.
μ