CISB241
In conducting a test of independence for a contingency table that has 4 rows and 3 columns, the number of degrees of freedom is 11
false
In conducting one-way analysis of variance, the sample size for each group must be equal.
false
At a sawmill in Oregon, a process improvement team measured the diameters for a sample of 1,500 logs. The following summary statistics were computed: Q1 = 8.7 in. Q2 = 13.5 in. Q3 = 15.4 in in. Given this information, the boundaries on the box in a box and whisker plot are: Question options: A) 8.7 in and 15.4 in. B) 13.5 in +- 1.5 (Q3-Q1). C) 8.7 in and 14.2 in. D) 14.2 in +- 1.5 (Q3-Q1).
A) 8.7 in and 15.4 in.
A study of a soda filling machine revealed that the mean fill of a can is 12 ounces with a standard deviation of 0.2 ounces. We want to find the probability that a can will be more than 12.3 ounces. The following is a graphic representation of the problem. Which of the following is not true? Question options: A) =norm.dist(12.3,12,0.2,true)= .0668 B) There is a 6.7% probability that a randomly selected can of soda will contain more than 12.3 ounces. C) To find the probability in the right tail, you need to use 1-norm.dist. In this case =1-norm.dist(12.3,12,.2,true) = 1- .9332 = .0668 D) There is a 93.3% chance that a randomly selected can will have 12.3 ounces or less.
A) =norm.dist(12.3,12,0.2,true)= .0668
Which of the following is NOT true of a bar chart? Question options: A) A bar chart is used for numeric data and shows the shape and distribution of the data. B) The bars show totals/values for various categories (nominal or ordinal data). C) The bars can be either horizontal or vertical. D) A bar chart typically has spaces between the bars.
A) A bar chart is used for numeric data and shows the shape and distribution of the data.
Which of the following would not be classical probability assessment? Question options: A) A new product is introduced at a grocery store, the distribution manager for the product guesses that 1 in 35 customers will buy the product. B) In business when there are five companies who submit a bid on a contract. Before any other factors are reviewed, company A's bid chances would be 1 in 5. C) In playing the game Monopoly, the probability of a player landing on Park Place. D) In the card game black jack, the probability of getting getting two jacks in a deck of 52 cards.
A) A new product is introduced at a grocery store, the distribution manager for the product guesses that 1 in 35 customers will buy the product.
In conducting a one-way analysis of variance where the critical value = 41.2 and the test statistic = 31.6, which of the following is correct? Question options: A) Conclude that all means are the same and there is no need to conduct the Tukey-Kramer procedure B) Conclude that the means are not all the same and that that the Tukey-Kramer procedure is not needed C) Conclude that all means are the same and that the Tukey-Kramer procedure should be conducted D) Conclude that the means are not all the same and that that the Tukey-Kramer procedure should be conducte
A) Conclude that all means are the same and there is no need to conduct the Tukey-Kramer procedure
In a contingency analysis, the greater the difference between the actual and the expected frequencies, the larger the chi-square value and the more likely: Question options: A) H0 should be rejected. B) H0 should be accepted. C) we cannot determine H0. D) the smaller the test statistic will be.
A) H0 should be rejected.
Which of the following is not true about the basic rules of probability? Question options: A) It is possible to exceed a probability of 1. B) Probability of a possible outcome must be between 0 and 1. C) The sum of all possible outcomes in a sample space is 1. D) The probability of an event not happening is 1-P(event).
A) It is possible to exceed a probability of 1.
If a data set has 630 values that have been sorted from low to high, which value in the data set will be the 20th percentile? Question options: A) The average of the 126th and 127th values B) The 20th value C) None of the options. D) The 126th value
A) The average of the 126th and 127th values
A histogram is used to display which of the following characteristics for a quantitative variable? A) The shape of the distribution B) The approximate center of the data C) All of the options are true D) The spread in the data
A) The shape of the distribution B) The approximate center of the data C) All of the options are true--- D) The spread in the data
Which of the following is the most frequently used measure of variation? Question options: A) The standard deviation B) The mode C) The range D) The variance
A) The standard deviation
A value(x) is converted to a standard normal distribution with a z score = 1.5 and is graphed as follows: What does this tell you about the value(x)? Question options: A) The value is 1.5 standard deviations larger than the mean. B) None of the options are true. C) The value is 1.5 times larger than the mean. D) The value is 1.5 times less likely than other values.
A) The value is 1.5 standard deviations larger than the mean.
For which data collection method is it most important to have a polished-looking survey form? Question options: A) Written questionnaire B) Experimental design C) Personal interview D) Telephone survey
A) Written questionnaire
To show how the price of a stock has changed over the last 3 months, the best type of chart to use is: Question options: A) a line chart. B) a bar chart. C) a histogram. D) a pie chart.
A) a line chart.
An Internet service provider has the capability of tracking the time that each of its customers spends connected to the Internet during a month. These data would constitute: Question options: A) a population. B) a cluster sample. C) a simple random sample. D) a convenience sample.
A) a population.
A value computed from a population is called: A) a statistic. B) a parameter. C) a real number. D) a point estimate.
A) a statistic. B) a parameter.---- C) a real number. D) a point estimate.
Estimation and hypothesis testing are categories of: A) descriptive statistics. B) statistical charts. C) inferential statistics. D) numerical measurement.
A) descriptive statistics. B) statistical charts. C) inferential statistics.---- D) numerical measurement.
When the park ranger at Yellowstone National Park reports the average length of time that visitors spend in the park, he is using: A) histograms or bar charts. B) statistical charts. C) numerical measures. D) graphical tools.
A) histograms or bar charts. B) statistical charts. C) numerical measures.---- D) graphical tools.
The use of charts and graphs is an example of: A) hypothesis testing. B) inferential statistics. C) estimation. D) descriptive statistics.
A) hypothesis testing. B) inferential statistics. C) estimation. D) descriptive statistics.----
Some stores and restaurants have "tell us what you think" cards available for customers. Assuming that angry customers are more likely to take the time to fill these out, this is an example of: Question options: A) nonstatistical sampling. B) cluster sampling. C) stratified sampling. D) simple random sampling.
A) nonstatistical sampling.
When a marketing manager surveys a few of the customers for the purpose of drawing a conclusion about the entire list of customers, she is applying: A) quantitative models. B) numerical measures. C) descriptive statistics D) inferential statistics.
A) quantitative models.----- B) numerical measures. C) descriptive statistics D) inferential statistics.
When data are organized into levels, the highest data level is: A) ratio level data. B) nominal level data. C) ordinal level data. D) interval level data.
A) ratio level data.--- B) nominal level data. C) ordinal level data. D) interval level data.
The reason for using the t-distribution in a hypothesis test about the population mean is: Question options: A) the population standard deviation is unknown. B) it results in a lower probability of a Type I error occurring. C) the population is not normally distributed. D) it provides a smaller critical value than the standard normal distribution for a given sample size.
A) the population standard deviation is unknown.
One of the major challenges for developing a good written questionnaire or telephone survey instrument is that Question options: A) wording can influence responses. B) there will always be missed data. C) nonresponses are too high. D) bias cannot be controlled.
A) wording can influence responses.
The human resources department at a major high tech company recently conducted an employee satisfaction survey of 100 of its 3,000 employees. Data were collected on such variables as age, gender, marital status, current salary, level of overall satisfaction on a scale from 1 to 5, number of years with the company, and job title. Which of the variables would be classified as nominal level data? A) Age and years with the company B) Overall satisfaction C) Gender, marital status, and job title D) Age and gender
A) Age and years with the company B) Overall satisfaction C) Gender, marital status, and job title---- D) Age and gender
Which of the following types of questions provide the respondent with the greatest choice in responding to a question? Question options:A) Open-ended questionsB) Close-ended questionsC) Multiple choice questionsD) True/false questions
A) Open-ended
Which of the following statements is not consistent with the Central Limit Theorem? Question options:A) The Central Limit Theorem applies without regard to the size of the sample.B) The Central Limit Theorem applies to non-normal distributions.C) The Central Limit Theorem indicates that the sampling distribution will be approximately normal when the sample size is sufficiently large.D) The Central Limit Theorem indicates that the mean of the sampling distribution will be equal to the population mean.
A) The Central Limit Theorem applies without regard to the size of the sample
The first phase of a hypothesis test is to determine what we are testing. Which of the following is not mentioned as a type of hypothesis test? Question options: A) A status quo test to see if operations are running normally or if a situation has changed. B) A similarity test that proves a value is equal to a desired value. C) A research hypothesis to prove a product is superior than an existing product. D) A test in order to prove a claim.
B) A similarity test that proves a value is equal to a desired value.
In conducting a personal interview, what problem can result if the interviewer is allowed to arbitrarily decide who should be interviewed? Question options: A) Nonresponses B) Bias C) Missing data D) Poor response rate
B) Bias
A large retail company gives an employment screening test to all prospective employees. Franklin Gilman recently took the test and it was reported back to him that his score placed him at the 80th percentile. Therefore: Question options: A) Franklin was in the bottom 20 percent of those that have taken the test. B) Franklin scored as high or higher than 80 percent of the people who took the test. C) 80 people who took the test scored below Franklin. D) Franlkin's score has a z-score of 80.
B) Franklin scored as high or higher than 80 percent of the people who took the test.
A company that makes shampoo wants to test whether the average amount of shampoo per bottle is 16 ounces. The standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.10 level of significance and a random sample of n = 64 bottles, which of the following would be the correct formulation of the null and alternative hypotheses? Question options: A) Ho: µ ≤ 16 Ha: µ > 16 B) Ho: µ = 16 Ha: µ ≠ 16 C) Ho: xbar = 16 Ha: xbar ≠ 16 D) Ho: µ ≥ 16 Ha: µ < 16 Question 81 / 1 point
B) Ho: µ = 16 Ha: µ ≠ 16
If an economist wishes to determine whether there is evidence that average family income in a community exceeds $25,000. The best null and alternative hypothesis is: Question options: A) Ho: µ = 25,000 Ha: µ ≠ 25,000. B) Ho: µ ≤ 25,000 Ha: µ > 25,000 C) Ho: µ > 25,000 Ha: µ ≤ 25,000
B) Ho: µ ≤ 25,000 Ha: µ > 25,000
An analyst plans to test whether the standard deviation for the time it takes bank tellers to provide service to customers exceeds the standard of 1.5 minutes. The currect null and alterhative hypothesis for this test are: Question options: A) Ho: σ ≤ 1.5 Ha: σ > 1.5 B) Ho: σ2 ≤ 2.25 Ha: σ2 > 2.25 C) Ho: σ2 > 2.25 Ha: σ2 ≤ 2.25 D) Ho: σ > 1.5 Ha: σ ≤ 1.5
B) Ho: σ2 ≤ 2.25 Ha: σ2 > 2.25
To use contingency analysis for numerical data, which of the following is true? Question options: A) Contingency analysis cannot be used for numerical data. B) Numerical data should be grouped into numeric ranges to get them into categories. C) Contingency analysis can be used for numerical data only if both variables are numerical. D) Contingency analysis can be used for numerical data only if it is interval data.
B) Numerical data should be grouped into numeric ranges to get them into categories.
The city counsel has just voted to pass the city's budget for next year. If you were writing a report describing the budget so the citizens could understand how the total tax dollars will be spent, which of the following graphs might be most appropriate? A) Histogram B) Pie chart C) Ogive D) Scatter diagram
B) Pie chart
Graphing a 90% confidence interval on a normal curve: Question options: A) The 90% is placed to the right with 10% in the lower tail. B) The 90% is centered with 5% in each tail. C) The 90% is centered with 10% in each tail. D) The 90% is placed to the left with 10% in the upper tail.
B) The 90% is centered with 5% in each tail.
In order for a one-way analysis of variance to be considered a balanced design, which of the following must hold? Question options: A) The population variances must be equal. B) The sample sizes selected from each population must be equal. C) The study must have the same number of rows as it does columns. D) All of the above are true.
B) The sample sizes selected from each population must be equal.
The following probability distribution has been assessed for the number of accidents that occur in a Midwestern city each day: Accidents Probability 0 0.25 1 0.20 2 0.30 3 0.15 4 0.10 This distribution is an example of: Question options: A) an expected value distribution. B) a discrete probability distribution. C) a continuous probability distribution. D) a normal distribution.
B) a discrete probability distribution.
A stem and leaf diagram is an alternative to using: Question options: A) a pie chart. B) a histogram. C) an ogive. D) a bar chart.
B) a histogram.
If a business manager selected a sample of customers and computed the mean income for this sample of customers, she has computed: Question options: A) a nominal value. B) an ordinal value. C) a parameter. D) a statistic.
B) an ordinal value.
A common rule of thumb for determining how many classes to use when developing a frequency distribution with classes is: Question options: A) at least 10 classes. B) between 5 and 20 classes. C) no fewer than 6 classes. D) equal to 0.25 times the number of data values.
B) between 5 and 20 classes.----
A population measure, such as the population mean (Mu) , is called a: Question options: A) statistic. B) parameter. C) sample value. D) prime number.
B) parameter.
A sample of people who have attended a college football game at your university has a mean = 3.2 members in their family. The mode number of family members is 3 and the median number is 4.0. Based on this information: Question options: A) the population mean exceeds 3.2. B) the distribution is left-skewed. C) the distribution is right-skewed. D) the distribution is bell-shaped.
B) the distribution is left-skewed.
The Empirical Rule states that for a bell-shaped distribution, approximately 95 percent of data should lie within Question options: A) three standard deviations from either side of the mean. B) two standard deviations from either side of the mean. C) one standard deviation from either side of the mean. D) four standard deviations from either side of the mean.
B) two standard deviations from either side of the mean.
f a hypothesis test for a single population variance is to be conducted using a significance level of to 0.10, a sample size of n = 16, and the test is a one-tailed upper-tail test, the critical value is: Question options: A) Χ2 = 24.9958. B) Χ2 = 22.3071. C) z = 1.28. D) t = 1.345.
B) Χ2 = 22.3071.
Joint frequency distributions are used to display: Question options:A) the histograms of two variables analyzed simultaneously.B) the number of occurrences at each of the possible joint occurrences of two variables.C) the cumulative distribution of a variable with two possible outcomes.D) the relative frequency of two variables.
B) the number of occurrences at each of the possible joint occurrences of two variables
A study was recently conducted by the regional electric and gas company. Data were collected for three customer categories showing the dollar amount of natural gas and the dollar amount of electricity consumed during the year. Which of the following graphs would most likely be used to compare the three customer categories? Question options: A) Line chart B) Pie chart C) Bar chart D) Histogram
C) Bar chart
Which one of the following is NOT statistical sampling? Question options: A) Stratified random sampling B) Cluster sampling C) Convenience sampling D) Simple random sample
C) Convenience sampling
The other method to determine probabilities for a standard normal distribution is to use Appendix D Standard Normal Distribution Table on page 764. Which of the following is not true? Question options: A) The row and column titles represent the z-score. B) The value on the inside of the chart represents the probability between the z-score and the middle of the bell curve. C) If the z-score is negative, the probability is negative. D) To use the chart you will use z=(xbar−μ)σto convert between the sample mean and the z-value.
C) If the z-score is negative, the probability is negative.
Below is an example of a desirable frequency distribution for a data set that has values between 146 and 425. ClassFrequency 146-185 4 186-225 16 226-265 33 266-305 26 306-345 21 346-385 9 386-425 1 Which of the following is not one of the characteristics? Question options: A) Mutually exclusive classes B) Equal-width classes C) Open-ended classes D) All-inclusive classes
C) Open-ended classes
Assume you are conducting a one-way analysis of variance using a 0.05 level of significance and have found that the p-value = 0.02. Which of the follow is correct regarding what you can conclude? Question options: A) Do not reject the null hypothesis; at least some of the means are different. B) Do not reject the null hypothesis; the means are all the same. C) Reject the null hypothesis; at least two of the means are different. D) Reject the null hypothesis; the mean are all the same.
C) Reject the null hypothesis; at least two of the means are different.
If a data set has 1,045 sorted values, what value corresponds to the 3rd quartile? Question options: A) The 783rd value B) The 261th value C) The 784th value D) Average of the 783rd and 784 value
C) The 784th value
When testing a two-tailed hypothesis using a significance level of 0.05, a sample size of n = 16, and s=5.2, which of the following is true? Question options: A) All options are correct. B) The test statistic will be a z-value. C) The alpha probability must be split in half with 2.5% in the lower tail and 2.5% in the upper tail. D) A sample size of 16 is not large enough to run a hypothesis test.
C) The alpha probability must be split in half with 2.5% in the lower tail and 2.5% in the upper tail.
A regression test was conducted to help in predicting the price of milk in Colorado (y) based on the gasoline prices in Florida (x). The results showed that there was a strong correlation (r=.85). In looking at the analysis a statistician said the results indicated a spurious correlation. What did the statistician mean by a spurious correlation? Question options: A) The correlation is valid and you can use the cost of gas in Florida to predict the cost of milk in Colorado. B) The test contained mathematical errors. C) The correlation is invalid because it is between two seemingly unrelated variables. D)
C) The correlation is invalid because it is between two seemingly unrelated variables.
How can the degrees of freedom be found in a contingency table with cross-classified data? Question options: A) The df are equal to numbers of rows minus the number of columns B) The df are equal to the number of rows multiplied by columns C) The df are equal to (number of rows minus 1) multiplied by (number of columns minus 1) D) The df are equal to the total number of cell minus 1
C) The df are equal to (number of rows minus 1) multiplied by (number of columns minus 1)
A study of a soda filling machine revealed that the mean fill of a can is 12 ounces with a standard deviation of 0.2 ounces. We want to find the probability that a can will be 11.8 ounces or less. The following is a graphic representation of the problem. To find P(x<=11.8), which of the following are true? Question options: A) Because we are working with continuous data, the P(x<=11.8) is the same as P(x<11.8). B) To find the probability you could use the Excel formula for a normal distribution =norm.dist(11.8, 12, 0.2, true)=.1587 C) To find the probability, you could use the Excel formula for the standard normal distribution =norm.s.dist(-1, true)=.1587 D) All of the options are true.
C) To find the probability, you could use the Excel formula for the standard normal distribution =norm.s.dist(-1, true)=.1587
Which of the following is a reason for constructing a joint frequency distribution? Product Issues by Manufacturing Plant CorrosionCracked LensWiringSoundRochester, NY30623916Miami, FL322248Houston, TX2664 Question options: A) To determine the trend between the two variables B) To show the average of two variables C) To help analyze the relationship between the two variables D) To measure the spread between the two variables
C) To help analyze the relationship between the two variables
Which of the following questions can NOT be answered using a scatter diagram? Question options: A) Is there a weak or strong relation between the 2 variables? B) Is there a curved or linear relation between the 2 variables? C) What is the trend over time of each of the 2 variables? D) Is there a positive or negative relation between the 2 variables?
C) What is the trend over time of each of the 2 variables?
sampling plan that requires a person to interview 100 people as they exit a department store would most likely be: Question options: A) a stratified sample. B) a systematic random sample. C) a convenience sample. D) a simple random sample.
C) a convenience sample.
The managers at Harris Pizza in Boston have tracked the tips received by their drivers along with the total bill to the customer. An appropriate graph for analyzing the relationship between these two variables is: Question options: A) a line chart. B) a histogram. C) a scatter diagram. D) a pie chart.
C) a scatter diagram.
When a hypothesis test is to be conducted regarding a population variance, the test statistic will be: Question options: A) a binomial distribution p value. B) a z-value from the standard normal distribution. C) a Χ2 value from the chi-square distribution. D) a t-value from the t-distribution.
C) a Χ2 value from the chi-square distribution.
The method of probability assessment that is least likely to be used by business decision makers is: Question options: A) subjective assessment. B) relative frequency of occurrence. C) classical assessment. D) None of the options.
C) classical assessment.
A regression analysis between sales (Y) and advertising (X) (both in dollars) resulted in the following equation: y = 100+200x The above equation implies that an Question options: A) increase of $10 in advertising is correlated with an increase of $100 in sales. B) increase of $10 in advertising is correlated with an increase of $2,000 in sales. C) increase of $10 in advertising is correlated with an increase of $2100 in sales. D) increase of $10 in advertising is correlated with an increase of $20 in sales.
C) increase of $10 in advertising is correlated with an increase of $2100 in sales.
When sampling from a population, the sample mean will: Question options: A) always be closer to the population mean as the sample size increases. B) typically exceed the population mean. C) likely be different from the population mean. D) likely be equal to the population mean if proper sampling techniques are employed.
C) likely be different from the population mean.
The most frequently used measure of central tendency is: Question options: A) median. B) mode. C) mean. D) middle value.
C) mean.
Your company wants to compare 3 similar products. One aspect is to test how long the product will last. Product research records 10 samples from each of the three products. A one-way ANOVA test concludes at least one mean is different. What is the q-value that is needed for the Tukey-Kramer test using Question options: A) q = 4.45 B) q = 3.96 C) q= 4.55 D) q = 5.27
C) q= 4.55
In order to compute the mean and standard deviation, the level of data measurement should be: Question options: A) qualitative. B) ordinal. C) ratio or interval. D) nominal.
C) ratio or interval.
A study was recently done in which 500 people were asked to indicate their preferences for one of three products. The following table shows the breakdown of the responses by gender of the respondents. Product Preference Gender A B C Male 80 20 10 Female 200 70 120 If the people conducting the study wish to assess the probability that product A will be preferred by members of the target population, the method of assessment to be used would most likely be: A) classical probability assessment. B) subjective assessment. C) relative frequency of occurrence. D) independent events.
C) relative frequency of occurrence.
A line chart is most appropriate for: Question options: A) nominal level data. B) ordinal level data. C) time-series data. D) cross-sectional data.
C) time-series data.
For a chi-square test involving a contingency table, suppose H0 is rejected. We conclude that the two variables are: Question options:A) curvilinear.B) linear.C) related.D) not related.
C) related
Which of the following data collection methods is most likely to generate the largest nonresponse? Question options: A) Personal interviews B) Telephone surveys C)Mail surveys D) Direct observation
C)Mail surveys
A car salesman has noted that the probability the dealiership sells a car on an Saturday morning is .25. The probability of the dealership not selling a car on Saturday morning is: Question options: A) 0.21 B) None of the options are true. C) 0.30 D) 0.75
D) 0.75
If a stratified random sample is to be conducted, which of the following is true? Question options: A) The population will be broken down into subgroups called strata. B) Each subgroup should contain items that are homogeneous with respect to the characteristic of interest. C) If effective, the total required sample size should be less than that which would be needed if a simple random sample were selected. D) All of the options are true.
D) All of the options are true.
Which of the following statements is true with respect to the t-distribution? Question options: A) The t-distribution is symmetrical. B) The exact shape of the t-distribution depends on the number of degrees of freedom. C) The t-distribution is more spread out than the standard normal distribution. D) All options are correct.
D) All options are correct.
A confidence interval on the mean: Question options: A) Calculates a range of possible values for the population mean. B) Is needed when the population mean is unknown and it is difficult to collect all possible values in the population. C) Uses a sample from the population to estimate the population mean. D) All options are true.
D) All options are true.
A study of a soda filling machine revealed that the mean fill of a can is 12 ounces with a standard deviation of 0.2 ounces. The probability a can is in the bottom 10% (under filled) if a can weight is what value or less. The following is a graphic representation of the problem. Which of the following is true? Question options: A) To find the z-score associated with the left 10% using Excel, =norm.s.inv(.10) = -1.28 rounded to two decimals. B) To find the x-value associated with the left 10% for a can of soda using Excel, =norm.inv(.10,12,.2) = 11.74 rounded to two decimals. C) There is a 10% probability that a randomly selected can of soda will have 11.74 ounces or less. D) All options are true.
D) All options are true.
Given the result of a contingency analysis is to reject Ho and the two categories are found to be dependent: Question options: A) This means the chi-square was larger enough to be in the upper tail. B) To find a potential pattern, you could review the cells where there is the largest difference between the observed and expected values that also have high chi-square values. C) Further study and testing will be needed to conducted to prove what the relationships might be. D) All options are true.
D) All options are true.
If a grouped column chart is made from data and it appears to be normally distributed, then it can be converted to a standard normal distribution. Which of the following is true about the standard normal distribution? Question options: A) The mean of the standard normal distribution is 0. B) The standard deviation of the standard normal distribution is 1. C) The formula used to convert a value is z=(x−μ)σ=(x−μ)/σ D) All options are true.
D) All options are true.
If a hypothesis test for a single population variance is to be conducted, which of the following statements is true? Question options: A) The null hypothesis must be stated in terms of the population variance. B) The chi-square distribution is used. C) If the sample size is increased, the critical value is also increased for a given level of statistical significance. D) All options are true.
D) All options are true.
When the the observed value of one or more cells is less than 5, which of the following is true? Question options: A) You could increase the overall sample size. B) You could try to combine categories when some categories have some natural fit together. C) If Ho is not rejected (there was not enough difference between the expected and observed values), then there is no issue with a Type I error and no need for further action. D) All options are true.
D) All options are true.
A recent study in the restaurant business determined: the mean tips for female waiters per hour of work are $6.78 with a standard deviation of $2.11, which gives a coefficient of variation of 31%. the mean tips per hour for male waiters are $7.86 with a standard deviation of $2.20, which gives a coefficient of variation of 28% Based on this information, which of the following statements do we know to be true? Question options: A) The distribution of tips for both males and females is right-skewed. B) The variation in tips received by females is more variable than males. C) The median tips for females exceeds that of males. D) Based on the coefficient of variation, females have more variation in tips per hour than do males.
D) Based on the coefficient of variation, females have more variation in tips per hour than do males.
A food warehouse manager plans to conduct a check on damaged packages. The warehouse covers a large area and products are spread out over the entire building. Assuming that no products are more likely to have damaged packages than any other, what statistical sampling method would be used to reduce the time and effort required to do the study? Question options: A) Convenience sampling B) Systematic random sampling C) Stratified random sampling D) Cluster random sampling
D) Cluster random sampling
Which of the following is not a characteristic of the normal distribution? Question options: A) Bell-shaped B) Mean=median=mode C) Symmetric D) Equal probabilities at all values of x
D) Equal probabilities at all values of x
Which of the following measures is not affected by extreme values in the data? Question options: A) The range B) The standard deviation C) The mean D) The median
D) The median
Which of the following applies to a point estimate? Question options: A) The point estimate is not needed to calculate a confidence interval. B) The point estimate is the same as the population parameter. C) The point estimate will be the same as the population mean if the sample size exceeds 30. D) The point estimate is subject to sampling error and will almost always be different from the population value.
D) The point estimate is subject to sampling error and will almost always be different from the population value.
In developing and conducting a survey, what is the purpose of the pre-test phase? Question options: A) To make sure that the cost of developing the survey instrument is not too great B) To generate initial data for analysis C) To make sure that the respondents like the issues being addressed by the survey D) To catch any problems with the questionnaire before it is fully administered
D) To catch any problems with the questionnaire before it is fully administered
Under what circumstances is it necessary to use the coefficient of variation to compare relative variability between two or more distributions? Question options: A) When the standard deviations of the distributions are equal B) When the means of the distributions are not equal C) When the means of the distributions are equal D) When the standard deviations of the distributions are not equal
D) When the standard deviations of the distributions are not equal
The general format for a confidence interval is: Question options: A) point estimate +- z (standard deviation). B) margin of error +- (confidence coefficient) (standard error). C) point estimate +- (critical value)(standard deviation) D) point estimate +- (critical value)(standard error).
D) point estimate +- (critical value)(standard error).
Portfolio A of a collection of stocks is considered more risky than portfolio B if Question options: A) portfolio A has a higher standard deviation. B) portfolio A has a higher mean than portfolio B. C) portfolio A has a higher variance than portfolio B. D) portfolio A has a higher coefficient of variation than portfolio B.
D) portfolio A has a higher coefficient of variation than portfolio B.
If a systematic random sample is to be selected of size 100 from a population with 5,000 items, the first item selected from the ordered population will be: Question options: A) item 50. B) any randomly selected value between 1 and 5,000. C) randomly selected between 1 and 100. D) randomly selected between 1 and 50.
D) randomly selected between 1 and 50.
A common method of probability assessment used in business is an examination of historical data from similar situations. This method is called: Question options: A) historical assessment. B) classical assessment. C) subjective assessment. D) relative frequency of occurrence.
D) relative frequency of occurrence.
The Polson Pole and Fence Company recently did a quality check on the length of fence posts. To do this, each of the 400 posts in inventory was numbered. Numbers from 1 to 400 were placed in a bowl. Twenty numbers were selected from the bowl without looking. These 20 poles were the ones selected for the study. This type of sampling is called: Question options: A) cluster sampling. B) nonstatistical. C) convenience sampling. D) simple random sampling.
D) simple random sampling.
One of the advantages that a stem and leaf diagram has over a histogram is: Question options: A) There are no advantages. B) it shows the general distribution of a quantitative variable. C) it can be used with nominal data. D) the detail of the data is preserved.
D) the detail of the data is preserved.
For ordinal data, ________ is the preferred measure of central location. Question options: A) the mean B) the quartile C) the percentile D) the median
D) the median
The purpose of a pilot sample is: Question options: A) to save time and money instead of having to carry out a full sampling plan. B) to provide a better idea of what the population mean will be. C) to help clarify how the sampling process will be performed. D) to provide an idea of what the population standard deviation might be.
D) to provide an idea of what the population standard deviation might be.
In analyzing the relationship between two numeric variables, a scatter plot can be used to detect which of the following? A) A positive linear relationship B) A curvilinear relationship C) A negative linear relationship D) No apparent pattern in the scattered points E) All of the options are true
E) All of the options are true
Descriptive statistics allow a decision maker to reach a conclusion about a populations based on a subset from the population.
False
When the United States conducts a census that counts all people in the country this is an example of using a sample.
False
A potato chip manufacturer has found that in the past the standard deviation of bag weight has been 0.2 ounces. They want to test whether the standard deviation has changed. The null hypothesis is: Question options: Ho: σ2 = 0.2 Ho: σ = 0.2 Ho: σ = 0.04 Ho: σ2 = 0.04
Ho: σ2 = 0.04
A histogram is most commonly used to analyze which of the following? Question options: A) Nominal level data B) Quantitative data C) Ordinal data D) Time-series data
Question options: A) Nominal level data B) Quantitative data---- C) Ordinal data D) Time-series data
Based on a survey of 400 students in a university in which 20 percent indicated that they were business majors. The university student newspaper reported that "20 percent of all the students at the university are business majors." This report is an example of Question options: A) descriptive statistics. B) a sample. C) statistical inference. D) a population.
Question options: A) descriptive statistics. B) a sample. C) statistical inference.---- D) a population.
The Biltmore Hotel manager is getting ready to make a presentation that she hopes will justify adding additional staff. As part of the presentation, she has constructed charts and graphs. The general type of statistical analysis she is using is: Question options: A) estimation. B) descriptive statistics C) hypothesis testing. D) inferential statistics
Question options: A) estimation. B) descriptive statistics.---- C) hypothesis testing. D) inferential statistics
A college database includes the number of people who are enrolled in each class the college offers. This is an example of: Question options: A) nominal data. B) ordinal data. C) interval data. D) ratio data.
Question options: A) nominal data. B) ordinal data. C) interval data. D) ratio data.---
General Electric Corporation tracks employee turnover annually. It currently has a data set that contains turnover for the past 20 years. What type of data does it have? Question options: A) Time-series data B) Cross-sectional data C) Nominal data D) Ordinal data
Question options: A) Time-series data--- B) Cross-sectional data C) Nominal data D) Ordinal data
When a survey uses the responses strongly disagree, disagree, neutral, agree, strongly agree, this is an example of: Question options: A) nominal data. B) ordinal data. C) interval data. D) ratio data.
Question options: A) nominal data. B) ordinal data.---- C) interval data. D) ratio data.
At the end of the school term, students are asked to rate the course and instructor by indicating on a scale of 1-5 how well they liked the course. The data generated from this question are examples of ordinal data.
True
Statistics is a discipline that involves tools and techniques used to describe data and draw conclusions
True
A correlation coefficient (r) of -0.9 indicates a weak linear relationship between the variables.
false
A large tire manufacturing company has claimed that its top line tire will average more than 80,000 miles. If a consumer group wished to test this claim, they would formulate the following null and alternative hypotheses: Ho: μ ≥ 80,000 Ha: μ ≠ 80,000
false
A recent study of students at the university contained data on year in school and student age. An appropriate tool for analyzing the relationship between these two variables would be a joint frequency distribution followed by a contingency analysis.
false
A sample can be assumed normally distributed if n ≥ 30.
false
A sample of n observations is taken from a normally distributed population to estimate the population variance. The degrees of freedom for the chi-square distribution are n-2.
false
A sample proportion can be assumed normally distributed if n ≥ 30.
false
Decreasing the level of confidence increases the width of confidence interval.
false
If a hypothesis test is conducted for a population mean, a null and alternative hypothesis of the form: Ho: μ = 100 Ha: µ ≠ 100 will result in a one-tailed hypothesis test since the sample result can fall in only one tail.
false
If the R-squared value for a regression model is high, the regression model will necessarily provide accurate forecasts of the y variable.
false
If the z=2.5789, using =norm.s.dist(2.5789,true) will give the exact same answer as using the book Appendix D for z=2.58.
false
If two variables are highly correlated, it not only means that they are linearly related, it also means that a change in one variable will cause a change in the other variable.
false
In a one-way analysis of variance test, the following null and alternative hypotheses are appropriate: Ho: μ1 = μ2 = μ3 Ha: μ1 ≠ μ2 ≠ μ3
false
In a scatter plot the points should always be connected with a line.
false
In order to assume that the sampling distribution for a proportion is approximately normal, the population proportion must be very close to 0.50.
false
It is appropriate to use a t-score using the pilot sample size instead of z in following equation to find the needed sample size? n = (z*stdeve)2
false
Sampling error can be eliminated if the sample size is large enough.
false
Sampling error can be eliminated if the sampling is done properly.
false
Suppose it is known that 93 percent of all parts in an inventory of 18,900 parts are in workable order. If a sample of n = 100 parts were selected from the inventory, based on the concept of sampling distributions of proportions, it can be assumed that the sample proportion of workable parts will also be 0.93.
false
The police chief in a local city claims that the average speed for cars and trucks on a stretch of road near a school is at least 45 mph. If this claim is to be tested, the null and alternative hypotheses are: Ho: µ < 45 Ha: µ ≥ 45
false
The symbol μ(Mu) is used to represent the sample mean.
false
The test statistic that is used when testing a null hypothesis for a population variance is the standard normal z-value.
false
Typically, it is possible to include more questions in a phone survey than in a mail survey since it takes less time to complete the survey over the phone.
false
When a group of university students takes a poll of their fellow students on whether they support a proposed fee increase, the sampling method they would use when students walking near the library are surveyed would be called a random sample.
false
When a variance is calculated for a data set, the resulting value is the same regardless of whether the data set is treated as a population or a sample.
false
When choosing class boundaries for a frequency distribution, classes such as 60-70, 70-80, 80-90 would be acceptable.
false
When constructing a scatter plot, the dependent variable (what we are trying to predict) is placed on the vertical y-axis and the independent variable is placed on the horizontal x-axis.
false
For proportions, if n*pbar > 5 and n*(1-pbar) > 5, which sampling distribution can be used? Question options: binomial distribution another sample must be taken to get it to 50% normal distribution we can use proportions without using a distribution
normal distribution
Contingency analysis helps to make decisions when multiple proportions are involved.
treu
In conducing one-way analysis of variance, the population distributions are assumed normally distributed.
treu
A 95% confidence interval on the mean tells us that 95% of all possible samples will have the population mean within the calculated range.
true
A Parks and Recreation official surveyed 200 people at random who have used one of the city's parks. The survey revealed that 26 resided outside the city limits. If she had to arrive at one single value to estimate the true proportion of park users who are residents of the city it would be 0.13.
true
A common underpinning of all statistical sampling techniques is the concept of random selection.
true
A correlation coefficient (r) is computed from a sample and is subject to sampling error. The hypothesis test to see if there the correlation coeffiecent is 0 (meaning no correlation) would use the greek r which is represented as
true
A critical value for a hypothesis test on a mean could be the z or t value that is associated with the acceptable percent of error (alpha) in the tail(s) of the curve. These can be found using either =norm.s.inv(%) or t.inv(%,n-1).
true
A joint frequency distribution and contingency analysis can only be completed when the original data is quantitative (numeric data).
true
A sample is selected from a population in cases where selecting data from the entire population is either very difficult or very expensive.
true
A sampling distribution for Xbar is the distribution of all possible sample means that could be computed from the possible samples of a given sample size.
true
A short survey with closed-end questions is likely to have a better response rate than a long survey with open-ended questions.
true
A study of 4000 Dell PC customers listed the age of the customer among other variables. The youngest customer was 14 years old and the oldest customer was 84 years old. If analysts for the company wish to develop a frequency distribution with 7 classes, the smallest value that the class width can be is 10 years.
true
An expected cell value of 5 or more is important to ensure an error is not made in the decision making process.
true
An increase in sample size will tend to result in less sampling error.
true
Assume that n = 18 people are asked a yes/no survey question, and 6 people say "yes" while 12 people say "no." Based on this information the sample proportion can be assumed normally distributed.
true
Based on the empirical rule we can assume that all distributions have approximately 95 percent of the values within +- 2 standard deviations of the mean.
true
Data are considered to be left-skewed when the mean lies to the left of the median on a number line.
true
For a given significance level, increasing the sample size will tend to increase the chi-square critical value used in testing the null hypothesis about a population variance.
true
For the same data, a graph of a relative frequency distribution will look exactly the same as a graph of the frequency distribution.
true
Hypothesis testing is about proving something beyond a reasonable doubt.
true
If the coefficient of determination is .45, this can be interpreted as 45% of the variation in the y-variable can be explained by knowing the x-variable.
true
In Excel a joint frequency distribution table can be created using a tool called PivotTable.
true
In a contingency analysis the expected values are based on the assumption that the two variables are independent of each other.
true
In determining the required sample size when estimating a population proportion, it is good practice to start with some idea of what that proportion is.
true
Managers use contingency analysis to determine whether two categorical variables are independent of each other.
true
Of the two types of statistical errors, the one that decision makers have most control over is Type I error (the value of alpha).
true
On a survey, the questions pertaining to the background of the respondent (age, gender, etc.) are referred to as demographic questions.
true
One of the things that the Central Limit Theorem tells us is that about half of the sample means will be greater than the population mean and about half will be less.
true
Recently, a company tested three different machine types to see if there was a difference in the mean thickness of products produced by the three. A random sample of ten products was selected from the output from each machine. Given this information, the proper design to test whether the means are equal is a one-way ANOVA balanced design.
true
Sampling error is the difference between the sample mean and the population mean.
true
Some of the most common methods of collecting data include experiments, telephone surveys, mail questionnaires, online surveys, direct observations and personal interviews.
true
Sometime it is necessary to assign probabilities based on a person's belief that an outcome will occur, this is called subjective probability assessment.
true
The following regression model has been computed based on a sample of twenty observations: y = 34.2 + 19.3x Given this model, the predictive model for y when x=40 is 806.2.
true
The graph of a discrete random variable looks like a histogram where the probability of each possible outcome is represented by a bar.
true
The interquartile range contains the middle 50 percent of a data set.
true
The mean of a sampling distribution would be equal to the mean of the population from which the sampling distribution is constructed.
true
The one sure thing that can be said about a point estimate is that it will most likely be subject to sampling error and not equal the parameter.
true
The one-way ANOVA test involves assuming that the population variances are equal.
true
The only two types of random variables are discrete and continuous random variables.
true
The point estimate when calculating a confidence interval on the population average is the sample mean.
true
The proportions in the joint frequency table can be used to find relative probability for a specified category.
true
The results of a regression analysis indicate: WeeklySales$(y) = $1242 + $2.32 * Ad$Spent(x) Is it true that the equation tells us that for every $1 increase in Ad$Spent, the WeeklySales$ increases by $2.32?
true
The test statistic for the mean is the value calculated from the sample using =(xbar-µ)/(stdev/sqrt(n).
true
To employ contingency analysis, we set up a 2-dimensional table with rows and columns called a contingency table, which can also be referred to as a cross-tabulation or a joint frequency table.
true
When calculating a confidence interval, the reason for using the t-distribution rather than the normal distribution for the critical value is that the population standard deviation is unknown.
true
When calculating n-size based on a desired margin of error and confidence level, if you find that n=45.2, you should round up to n=46 to make sure you have a sample size large enough.
true
When determining sample size for a proportion, using pbar = 0.5 will produce the largest possible value for n.
true
When the slope in the regression equation is negative, the correlation coefficient (r) will always be negative
true
When using a chi-square test for the variance of one population, we are assuming that the population is normally distributed.
true
The coefficient of determination (R Square) is always found by taking the correlation coefficient (r) and squaring it.
truue
