ISDS 2000 - Final Cope
How many parameters are needed to fully describe any normal distribution? 1 2 3 4
2
In a two-way ANOVA test, how many null hypotheses are tested? 1 1 or 2 2 or 3 More than 3
2 or 3
A market researcher is studying the spending habits of people across age groups. The amount of money spent by each individual is classified by spending category (Dining out, Shopping, or Electronics) - Factor A, and generation (Gen-X, Gen-Y, Gen-Z, or Baby Boomers) - Factor B. An incomplete ANOVA table is shown below. How many degrees of freedom are there for factors A and B? 2, 3 3, 4 3, 6 2, 4
2, 3
The accompanying table shows the regression results when estimating y = β0 + β1x + ε Which of the following is the value of the test statistic when testing whether x significantly influences y? 0.66 1.42 1.96 2.25
2.25
What is tα/2,df for a 99% confidence interval of the population mean based on a sample of 25 observations? 2.492 2.576 2.787 2.797
2.797
The ANOVA test performed for determined that not all mean commute times across the four cities are equal. However, it did not indicate which means differed. To find out which population means differ requires further analysis of the direction and the statistical significance of the difference between paired population means. Fisher 95% confidence intervals are shown below. How many pairs of cities show a significant difference in average commute times to work? 2 3 4 6
4
The choice of an appropriate test for comparing two population means depends on whether we deal with _________ . qualitative or quantitative data independent or matched-pairs sampling the equality or lack of equality of population variances All of these choices are correct
qualitative or quantitative data independent or matched-pairs sampling the equality or lack of equality of population variances
Two or more random samples are considered independent if _________ . the process that generates one sample is the same as the process that generates the other sample the process that generates one sample is related to the process that generates the other sample the process that generates one sample is influenced by the process that generates the other sample the process that generates one sample is completely separate from the process that generates the other sample
the process that generates one sample is completely separate from the process that generates the other sample
Which of the following variables is qualitative? Height Gender Weight Temperature
Gender
A restaurant chain has two locations in a medium-sized town and, believing that it has oversaturated the market for its food, is considering closing one of the restaurants. The manager of the restaurant with a downtown location claims that his restaurant generates more revenue than the sister restaurant by the freeway. The CEO of this company, wishing to test this claim, randomly selects 36 monthly revenue totals for each restaurant. The revenue data from the downtown restaurant have a mean of $360,000 and a standard deviation of $50,000, while the data from the restaurant by the freeway have a mean of $340,000 and a standard deviation of $40,000. Assume there is no reason to believe the population standard deviations are equal, and let μ1 and μ2 denote the mean monthly revenue of the downtown restaurant and the restaurant by the freeway, respectively. Which of the following hypotheses should be used to test the manager's claim? H0: µ1 - µ2 ≤ 0, HA: µ1 - µ2 > 0 H0: µ1 - µ2 ≥ 0, HA: µ1 - µ2 < 0 H0: µ1 - µ2 = 0, HA: µ1 - µ2 ≠ 0 H0: µ1 - µ2 > 0, HA: µ1 - µ2 ≤ 0
H0: µ1 - µ2 ≤ 0, HA: µ1 - µ2 > 0
When using a polygon to graph quantitative data, what does each point represent? The lower limit of a particular class and its width The midpoint of a particular class and its associated frequency or relative frequency The midpoint of a particular class and its associated cumulative frequency or cumulative relative frequency The upper limit of a particular class and its associated cumulative frequency or cumulative relative frequency
The midpoint of a particular class and its associated frequency or relative frequency
How do the tdf and z distributions differ? There is no difference between the tdf and z distributions; they both do not have asymptomatic tails. The z distribution has broader tails (it is flatter around zero). The tdf distribution has broader tails (it is flatter around zero). The z distribution has asymptotic tails, while the tdf distribution does not.
The tdf distribution has broader tails (it is flatter around zero).
What is the purpose of calculating a confidence interval? To provide a range of values that has a certain large probability of containing the sample statistic of interest. To provide a range of values that, with a certain measure of confidence, contains the sample statistic of interest. To provide a range of values that, with a certain measure of confidence, contains the population parameter of interest. To provide a range of values that has a certain large probability of containing the population parameter of interest.
To provide a range of values that, with a certain measure of confidence, contains the population parameter of interest.
What is(are) the most widely used measure(s) of dispersion? Multiple Choice Range Interquartile range Variance and standard deviation Covariance and the correlation coefficient
Variance and standard deviation
Consider the following data: x = 20, sx = 2, y = −5, sy = 4, and b1 = −0.8. Which of the following is the sample regression equation? yˆ= −21 − 0.80x yˆ= −21 + 0.80x yˆ= 11 − 0.80x yˆ= 11 + 0.80x
yˆ= 11 − 0.80x
Consider the following simple linear regression model: y = β0 + β1x + ε. The random error term is ________. y x ε β0
ε
A statistics student is asked to estimate y = β0 + β1x + ε. She calculates the following values: Σxi=220, Σ(xi−x)^2 = 440, Σ(xi−x)(yi−y)=−568, Σyi=385, Σ(yi−y)^2 = 1,120, n = 11. The value of the slope b1 is ____. −1.29 −0.51 0.51 1.29
−1.29
A sample regression equation is given by yˆ= −100 + 0.5x. If x = 20, the predicted value of y is ________. −80 −90 110 120
−90
A marketing analyst wants to examine the relationship between sales (in $1,000s) and advertising (in $100s) for firms in the food and beverage industry and collects monthly data for 25 firms. He estimates the model: Sales = β0 +β1 Advertising + ε. The following ANOVA table shows a portion of the regression results. Which of the following is the predicted Sales for a firm with Advertising of $500? $1,480 $40,100 $54,500 $148,000
$54,500
In a simple linear regression model, if the points on a scatter diagram lie on a straight line with a negative slope, which of the following is the coefficient of determination? −1 0 +1 Infinity
+1
How do we find the median if the number of observations in a data set is odd? By averaging the first and the third quartile By taking the middle value in the sorted data set By averaging the minimum and maximum values By taking the middle value in the sorted data set after eliminating outliers
By taking the middle value in the sorted data set
The height of the probability density function f(x) of the uniform distribution defined on the interval [a, b] is ______. 1/(b - a) between a and b, and zero otherwise (b - a)/2 between a and b, and zero otherwise (a + b)/2 between a and b, and zero otherwise 1/(a + b) between a and b, and zero otherwise
1/(b - a) between a and b, and zero otherwise
If there are five treatments under study, the number of pairwise comparisons is _______. 15 5 20 10
10
The minimum sample size n required to estimate a population mean with 95% confidence and the desired margin of error 1.5 was found to be 198. Which of the following is the approximate value of the assumed estimate of the population standard deviation? 10.7690 12.8309 115.9671 164.6326
10.7690
A politician wants to estimate the percentage of people who like his new slogan. Given that no prior estimate of the population proportion is available, what is the minimum sample size such that the margin of error is no more than 0.08 for a 95% confidence interval? 105.70 106 150.06 151
151
When a characteristic of interest differs among various observations, then it can be termed a parameter variable. data. information.
variable
A correlation coefficient r = −0.85 could indicate a ________. very weak positive linear relationship very strong negative linear relationship very weak negative linear relationship very strong positive linear relationship
very strong negative linear relationship
A 90% confidence interval is constructed for the population mean. If a 95% confidence interval had been constructed instead (everything else remaining the same), the width of the interval would have been ________ and the probability of making an error would have been _________. wider; bigger wider; smaller narrower; bigger narrower; smaller
wider; smaller
Excel and virtually all other statistical packages report the p-value ________. for a two-tailed test that assesses whether the regression coefficient differs from one for a right-tailed test that assesses whether the regression coefficient is greater than zero for a two-tailed test that assesses whether the regression coefficient differs from zero for a left-tailed test that assesses whether the regression coefficient is less than zero
for a two-tailed test that assesses whether the regression coefficient differs from zero
In order to summarize qualitative data, a useful tool is a __________. histogram frequency distribution stem-and-leaf diagram All of the above
frequency distribution
In regression, multicollinearity is considered problematic when two or more explanatory variables are ________. not correlated rarely correlated highly correlated moderately correlated
highly correlated
When comparing two population means, their hypothesized difference _________ . must be negative must be positive must be zero may assume any value
may assume any value
The ordinal scale of data measurement is less sophisticated than the nominal scale. more sophisticated than the interval scale. more sophisticated than the nominal scale. as equally sophisticated as the nominal scale.
more sophisticated than the nominal scale.
The mode is defined as the _____________. middle point in a data set. geometric average of a data set. arithmetic average of a data set. most frequent value in a data set.
most frequent value in a data set.
In general, the null and alternative hypotheses are __________. additive correlated multiplicative mutually exclusive
mutually exclusive
What is the minimum sample size required to estimate a population mean with 95% confidence when the desired margin of error is E = 1.5? The population standard deviation is known to be 10.75. n = 138 n = 139 n = 197 n = 198
n = 198
Find the minimum sample size when we want to construct a 90% confidence interval on the population proportion for the support of candidate A in the following mayoral election. Candidate A is facing two opposing candidates. In a preselected poll of 100 residents, 22 supported her. The desired margin of error is 0.08. n = 44 n = 72 n = 73 n = 103
n = 73
A respondent of a survey is asked whether the Philadelphia Flyers' performance in the last game was excellent, good, fair, or poor. The person indicates that the performance was "good." This is an example of nominal data ordinal data interval data ratio data
ordinal data
The owner of a large car dealership believes that the financial crisis decreased the number of customers visiting her dealership. The dealership has historically had 800 customers per day. The owner takes a sample of 100 days and finds the average number of customers visiting the dealership per day was 750. Assume that the population standard deviation is 350. The value of the test statistic is ____________. z = -1.429 t99 = -1.429 z = 1.429 t99 = 1.429
z = -1.429
What is zα/2 for a 95% confidence interval of the population mean? 0.48 0.49 1.645 1.96
1.96
A multiple regression model with two explanatory variables is estimated using 20 observations resulting in SSE = 550 and SST = 1000. Which of the following is the correct value of R2? 0.10 0.45 0.55 0.90
0.45
The following is an incomplete ANOVA table. For the within groups category, the degrees of freedom are _____. 6 7 8 9
8
The sample data below shows the number of hours spent by five students over the weekend to prepare for Monday's Business Statistics exam. 3 12 2 3 5 The 75th percentile of the data is the closest to _________. 3 hours 4.5 hours 8.5 hours 10 hours
8.5 hours
A particular bank has two loan modification programs for distressed borrowers: Home Affordable Modification Program (HAMP) modifications, where the federal government pays the bank $1,000 for each successful modification, and non-HAMP modifications, where the bank does not receive a bonus from the federal government. To qualify for a HAMP modification, borrowers must meet a set of financial suitability criteria. What type of hypothesis test should we use to test whether borrowers from this particular bank who receive HAMP modifications are more likely to re-default than those who receive non-HAMP modifications? A hypothesis test for p1 - p2. A hypothesis test for µ1 - µ2. A matched-pairs hypothesis test. We are unable to conduct a hypothesis test because independent random samples of each group could not be collected.
A hypothesis test for p1 - p2.
Statisticians like precision in their interval estimates. A low margin of error is needed to achieve this. Which of the following supports this when selecting sample sizes? A larger sample size reduces the margin of error. A smaller sample size reduces the margin of error. A larger sample size increases the margin of error. A sample size has no impact on the margin of error.
A larger sample size reduces the margin of error.
A particular personal trainer works primarily with track and field athletes. She believes that her clients run faster after going through her program for six weeks. How might she test that claim? A hypothesis test for p1−p2. A hypothesis test for μ1−μ2· A matched-pairs hypothesis test for μD. We are unable to conduct a hypothesis test because the samples would not be independent.
A matched-pairs hypothesis test for μD.
Let X be normally distributed with mean μ and standard deviation σ > 0. Which of the following is true about the z value corresponding to a given x value? A positive z = (x - μ)/σ indicates how many standard deviations x is above μ. A negative z = (x - μ)/σ indicates how many standard deviations x is below μ. The z value corresponding to x = μ is zero. All of the above.
A positive z = (x - μ)/σ indicates how many standard deviations x is above μ. A negative z = (x - μ)/σ indicates how many standard deviations x is below μ. The z value corresponding to x = μ is zero.
How does an ogive differ from a polygon? An ogive is used for qualitative data, while a polygon is used for quantitative data. An ogive is used for quantitative data, while a polygon is used for qualitative data. An ogive is a graphical depiction of a frequency or relative distribution, while a polygon is a graphical depiction of a cumulative frequency or cumulative relative frequency distribution. An ogive is a graphical depiction of a cumulative frequency or cumulative relative frequency distribution, while a polygon is a graphical depiction of a frequency or relative frequency distribution.
An ogive is a graphical depiction of a cumulative frequency or cumulative relative frequency distribution, while a polygon is a graphical depiction of a frequency or relative frequency distribution.
Which of the following identifies the range for a correlation coefficient? Any value less than 1. Any value greater than 0. Any value between 0 and 1. Any value between −1 and 1.
Any value between −1 and 1.
Which of the following is true when using the empirical rule for a set of sample data? Almost all observations are in the interval x+/-2s. Approximately 68% of all observations are in the interval x+/-s Approximately 95% of all observations are in the interval x+/-s Approximately 68% of all observations are in the interval x+/-2s
Approximately 68% of all observations are in the interval x+/-s
Given the following portion of regression results, which of the following conclusions is true with regard to the F test at the 5% significance level? Neither of the explanatory variables is related to the response variable. Both of the explanatory variables are related to the response variable. Exactly one of the explanatory variables is related to the response variable. At least one of the explanatory variables is significantly related to the response variable.
At least one of the explanatory variables is significantly related to the response variable.
When displaying quantitative data, what is an ogive used to plot? Frequency or relative frequency of each class against the midpoint of the corresponding class Cumulative frequency or cumulative relative frequency of each class against the upper limit of the corresponding class Frequency or relative frequency of each class against the midpoint of the corresponding class and cumulative frequency or cumulative relative frequency of each class against the upper limit of the corresponding class None of the above
Cumulative frequency or cumulative relative frequency of each class against the upper limit of the corresponding class
What is the name of the variable that is used to predict another variable? Response Explanatory Coefficient of determination Standard error of the estimate
Explanatory
A demographer wants to measure life expectancy in countries 1 and 2. Let μ1 and μ2 denote the mean life expectancy in countries 1 and 2, respectively. Specify the hypothesis to determine if life expectancy in country 1 is more than 10 years lower than in country 2. H0: µ1 - µ2 ≤ 10, HA: µ1 - µ2 > 10 H0: µ1 - µ2 ≥ 10, HA: µ1 - µ2 < 10 H0: µ1 - µ2 ≤ -10, HA: µ1 - µ2 > −10 H0: µ1 - µ2 ≥ -10, HA: µ1 - µ2 < −10
H0: µ1 - µ2 ≥ -10, HA: µ1 - µ2 < −10
A police chief wants to determine if crime rates are different for four different areas of the city (East(1), West(2), North(3), and South(4) sides), and obtains data on the number of crimes per day in each area. The one-way ANOVA table is shown below. The competing hypotheses about the mean crime rates are__________________________________________. H0: μ1 = μ2 = μ3, HA: Not all population means are equal H0: Not all population means are equal, HA: μ1 = μ2 = μ3 H0: μ1 = μ2 = μ3 = μ4, HA: Not all population means are equal H0: Not all population means are equal, HA: μ1 = μ2 = μ3 = μ4
H0: μ1 = μ2 = μ3 = μ4, HA: Not all population means are equal
Consider the following simple linear regression model: y = β0 + β1x + ε. When determining whether x significantly influences y, the null hypothesis takes the form ________. H0:β1 = 0 H0:β1 = 1 H0:b1 = 0 H0:b1 = 1
H0:β1 = 0
Which of the following are two-tailed tests? Ho:μ ≤ 10, HA:μ > 10 Ho:μ = 10, HA:μ ≠ 10 Ho:μ ≥ 400, HA:μ < 400 Both Ho:μ ≤ 10, HA:μ > 10 and Ho:μ ≥ 400, HA:μ < 400
Ho:μ = 10, HA:μ ≠ 10
A university is interested in promoting graduates of its honors program by establishing that the mean GPA of these graduates exceeds 3.50. A sample of 36 honors students is taken and is found to have a mean GPA equal to 3.60. The population standard deviation is assumed to equal 0.40. To establish whether the mean GPA exceeds 3.50, the appropriate hypotheses are ______________. Ho:μ≤3.50,HA:μ>3.50 Ho:X−≤3.50,HA:X−>3.50 Ho:μ≥3.50,HA:μ<3.50 Ho:X−≥3.50,HA:X−<3.50
Ho:μ≤3.50,HA:μ>3.50
Expedia would like to test if the average round-trip airfare between Philadelphia and Dublin is less than $1,200. The correct hypothesis statement would be __________________________. Ho:μ≠$1,200,HA:μ=$1,200 Ho:μ<$1,200,HA:μ≥$1,200 Ho:μ≥$1,200,HA:μ<$1,200 Ho:μ=$1,200,HA:μ≠$1,200
Ho:μ≥$1,200,HA:μ<$1,200
Suppose you want to perform a test to compare the mean GPA of all freshmen with the mean GPA of all sophomores in a college? What type of sampling is required for this test? Independent sampling with qualitative data Independent sampling with quantitative data Matched-pairs sampling with qualitative data Matched-pairs sampling with quantitative data
Independent sampling with quantitative data
A continuous random variable has the uniform distribution on the interval [a, b] if its probability density function f(x) ______. Provides all probabilities for all x between a and b Is bell-shaped between a and b Is constant for all x between a and b, and 0 otherwise Asymptotically approaches the x axis when x increases to +∞ or decreases to -∞
Is constant for all x between a and b, and 0 otherwise
statistic is t20 = 1.95 with a corresponding p-value of 0.0653. At the 5% significance level, can you conclude that the correlation coefficient differs from zero? Yes, since the p-value exceeds 0.05. Yes, since the test statistic value of 1.95 exceeds 0.05. No, since the p-value exceeds 0.05. No, since the test statistic value of 1.95 exceeds 0.05.
No, since the p-value exceeds 0.05.
Which of the following is appropriate to conduct a hypothesis test for the difference between two population proportions under independent sampling. Multiple Choice In every case. Only if n1≥30 and n2≥30 Only if n1p1≥5, n1(1-p1)≥5, n2p2≥5, and n2(1-p2)≥5. Only if n1p1≥30, n1(1−p1)≥30, n2p2≥30 and n2(1−p2)≥30.
Only if n1p1≥5,n1(1-p1)≥5, n2p2≥5, and n2(1-p2)≥5.
What is the decision rule when using the p-value approach to hypothesis testing? Reject Ho if the p-value > α. Reject Ho if the p-value < α. Do not reject Ho if the p-value < 1 - α. Do not reject Ho if the p-value > 1 - α.
Reject Ho if the p-value < α.
Which of the following statements is the least accurate concerning correlation analysis? Correlation does not imply causation. The correlation coefficient captures only a linear relationship. The correlation coefficient may not be a reliable measure when outliers are present in one or both of the variables. The correlation coefficient describes both the direction and strength of the relationship between two variables only if the two variables have the same units of measurement.
The correlation coefficient describes both the direction and strength of the relationship between two variables only if the two variables have the same units of measurement.
When using the empirical rule, which of the following assumptions is made? The data only comes from a sample. The data only comes from a population. The data are exactly symmetric and bell-shaped. The data are approximately symmetric and bell-shaped
The data are approximately symmetric and bell-shaped
Which of the following violates the assumptions of regression analysis? The error term is normally distributed. The error term has a zero mean. The error term is correlated with an explanatory variable. The error term has a constant variance.
The error term is correlated with an explanatory variable.
The national average for an eighth-grade reading comprehension test is 73. A school district claims that its eighth-graders outperform the national average. In testing the school district's claim, how does one define the population parameter of interest? The mean score on the eighth-grade reading comprehension test The number of eighth graders who took the reading comprehension test The standard deviation of the score on the eighth-grade reading comprehension test The proportion of eighth graders who scored above 73 on te reading comprehension test
The mean score on the eighth-grade reading comprehension test
Which of the following is the 95% confidence interval for the regression coefficient β1, if df = 30, b1 = −2 and sb1=3? [−5.00, −1.00] [−7.88, 3.88] [−7.09, 3.09] [−8.13, 4.13]
[−8.13, 4.13]
Is it possible for a data set to have no mode? Yes, if two observations occur twice. No, unless there is an odd number of observations. No, if the data set is nonempty, there is always a mode. Yes, if there are no observations that occur more than once.
Yes, if there are no observations that occur more than once.
n an examination of holiday spending (known to be normally distributed) of a sample of 16 holiday shoppers at a local mall, an average of $54 was spent per hour of shopping. Based on the current sample, the standard deviation is equal to $21. Find a 90% confidence interval for the population mean level of spending per hour. [$44.83, $63.17] [$44.79, $63.20] [$45.36, $62.63] [$46,96, $61.04]
[$44.79, $63.20]
A random sample of 130 mortgages in the state of Maryland was randomly selected. From this sample, 14 were found to be delinquent on their current payment. The 98% confidence interval for the proportion based on this sample is _______. [0.044, 0.171] [0.036, 0.180] [0.029, 0.188] [0.015, 0.201]
[0.044, 0.171]
We draw a random sample of size 25 from the normal population with variance 2.4. If the sample mean is 12.5, what is a 99% confidence interval for the population mean? [11.2600, 13.7400] [11.3835, 13.6165] [11.7019, 13.2981] [11.7793, 13.2207]
[11.7019, 13.2981]
A basketball coach wants to know how many free throws an NBA player shoots during the course of an average practice. The coach takes a random sample of 43 players and finds the average number of free throws shot per practice was 225 with a standard deviation of 35. Construct a 99% confidence interval for the average number of free throws in practice. [210.5992, 239.4008] [210.6155, 239.3845] [211.2506, 238.7494] [214.2290, 235.7710]
[210.5992, 239.4008]
Chebyshev's theorem is applicable when the data are___________________. any shape skewed to the left skewed to the right approximately symmetric and bell-shaped
any shape
Population parameters are difficult to calculate due to: cost prohibitions on data collection. the infeasibility of collecting data on the entire population. the fact that samples are difficult to draw due to the nature of the data. both cost prohibitions on data collection and the infeasibility of collecting data on the entire population.
both cost prohibitions on data collection and the infeasibility of collecting data on the entire population.
In regression, the two types of interval estimates concerning y are called ________. significance interval and prediction interval confidence interval and significance interval confidence interval and prediction interval significance interval and frequency interval
confidence interval and prediction interval
An analyst studies a data set of the year-end book value per share for all companies listed on the New York Stock Exchange. This data set is best described as time series data. cross-sectional data. neither time series nor cross-sectional data. a combination of time series and cross-sectional data.
cross-sectional data.
Your business statistics class had a test last week. The average score for the class is an example of secondary data qualitative data descriptive statistics inferential statistics
descriptive statistics
Horizontal bar charts are constructed by placing each category on the vertical axis and the appropriate range of values on the horizontal axis each category on the horizontal axis and the appropriate range of values on the vertical axis each interval of values on the vertical axis and the appropriate range of values on the horizontal axis None of the above
each category on the vertical axis and the appropriate range of values on the horizontal axis
In inferential statistics, we calculate statistics of sample data to: estimate unknown population parameters. conduct tests about unknown population parameters. Both of these choices are correct. Neither of these choices is correct.
estimate unknown population parameters. conduct tests about unknown population parameters.
Tukey's Honestly Significant Differences (HSD) method ensures that the probability of at least one Type I error remains fixed irrespective of the number of ________________. pairwise comparisons treatments replications within each treatment replications for each combination of factor A and factor B
pairwise comparisons
When using Fisher's LSD method with a given significance level for each interval, the probability of committing a Type I error for at least one comparison increases as the number of _________________________. pairwise comparisons decreases pairwise comparisons increases sample size increases treatments decreases
pairwise comparisons increases
A sample statistic is an estimate of population parameter. population statistic. sample parameter. descriptive statistic.
population parameter.
If the p-value for a hypothesis test is 0.027 and the chosen level of significance is α = 0.05, then the correct conclusion is to ________________. reject the null hypothesis not reject the null hypothesis reject the null hypothesis if σ = 10 not reject the null hypothesis if σ = 10
reject the null hypothesis
To test if the mean IQ of employees in an organization is greater than 100, a sample of 30 employees is taken and the value of the test statistic is computed as t29 = 2.42 If we choose a 5% significance level, we _____________. reject the null hypothesis and conclude that the mean IQ is greater than 100 reject the null hypothesis and conclude that the mean IQ is not greater than 100 do not reject the null hypothesis and conclude that the mean IQ is greater than 100 do not reject the null hypothesis and conclude that the mean IQ is not greater than 100
reject the null hypothesis and conclude that the mean IQ is greater than 100
A Type I error occurs when we ___________. reject the null hypothesis when it is actually true reject the null hypothesis when it is actually false do not reject the null hypothesis when it is actually true do not reject the null hypothesis when it is actually false
reject the null hypothesis when it is actually true
In regression, the predicted values concerning y are subject to ________. kurtosis skewness mean deviation sampling variation
sampling variation
Simple linear regression analysis differs from multiple regression analysis in that ________. simple linear regression uses only one explanatory variable the coefficient of correlation is meaningless in simple linear regression goodness-of-fit measures cannot be calculated with simple linear regression the coefficient of determination is always higher in simple linear regression
simple linear regression uses only one explanatory variable
The following scatterplot indicates that the relationship between the two variables x and y is ________. strong and positive strong and negative weak and negative no relationship
strong and positive
A newly hired basketball coach promised a high-paced attack that will put more points on the board than the team's previously tepid offense historically managed. After a few months, the team owner looks at the data to test the coach's claim. He takes a sample of 36 of the team's games under the new coach and finds that they scored an average of 101 points with a standard deviation of 6 points. Over the past 10 years, the team had averaged 99 points. What is the value of the appropriate test statistic to test the new coach's claim at the 1% significance level? t35 = 0.33 z = 0.33 t35 = 2.00 z = 2.00
t35 = 2.00
If the interaction between two factors is not significant, the next tests to be done are ___________________. Multiple Choice none, the analysis is complete none, gather more data tests about the population means of factor A or factor B using two-way ANOVA without interaction Tukey's confidence intervals
tests about the population means of factor A or factor B using two-way ANOVA without interaction
Fisher's LSD method is applied when the _________________. the ANOVA null hypothesis is rejected the ANOVA null hypothesis is not rejected either A or B occur neither A or B occur
the ANOVA null hypothesis is rejected
It is generally believed that no more than 0.50 of all babies in a town in Texas are born out of wedlock. A politician claims that the proportion of babies born out of wedlock is increasing. When testing the two hypotheses, H0>: p ≤ 0.50 and HA: p > 0.50, p stands for _____________. the current proportion of babies born out of wedlock the mean number of babies born out of wedlock the number of babies born out of wedlock the general belief that the proportion of babies born out of wedlock is no more than 0.50
the current proportion of babies born out of wedlock
A fast-food franchise is considering building a restaurant at a busy intersection. A financial advisor determines that the site is acceptable only if, on average, more than 300 automobiles pass the location per hour. The advisor tests the following hypotheses: Ho: μ ≤ 300. HA: μ > 300. The consequences of committing a Type I error would be that the franchiser builds on an acceptable site the franchiser builds on an unacceptable site the franchiser does not build on an acceptable site the franchiser does not build on an unacceptable site
the franchiser builds on an unacceptable site
The study of statistics can be defined as: the language of data. the art and science of getting information from data. the study of collecting, analyzing, presenting, and interpreting data. All of these choices are correct.
the language of data. the art and science of getting information from data. the study of collecting, analyzing, presenting, and interpreting data.
Consider the following sample regression equation yˆ= 200 + 10x, where y is the supply for Product A (in 1,000s) and x is the price of Product A (in $). The slope coefficient indicates that if ________. the price of Product A increases by $1, then we predict the supply to decrease by 10 the price of Product A increases by $1, then we predict the supply to increase by 10 the price of Product A increases by $1, then we predict the supply to decrease by 10,000 the price of Product A increases by $1, then we predict the supply to increase by 10,000
the price of Product A increases by $1, then we predict the supply to increase by 10,000
The ages of MBA students at a university are normally distributed with a known population variance of 10.24. Suppose you are asked to construct a 95% confidence interval for the population mean age if the mean of a sample of 36 students is 26.5 years. If a 99% confidence interval is constructed instead of a 95% confidence interval for the population mean, then _______________________________________________. the resulting margin of error will increase and the risk of reporting an incorrect interval will increase the resulting margin of error will decrease and the risk of reporting an incorrect interval will increase the resulting margin of error will increase and the risk of reporting an incorrect interval will decrease the resulting margin of error will decrease and the risk of reporting an incorrect interval will decrease
the resulting margin of error will increase and the risk of reporting an incorrect interval will decrease
One of the assumptions of regression analysis is ________. there is perfect multicollinearity among some explanatory variables there is no perfect multicollinearity among any explanatory variables there is some degree of multicollinearity among some explanatory variables None of these choices is correct.
there is no perfect multicollinearity among any explanatory variables
Assume the competing hypotheses take the following form H0: µ1 - µ2 = 0, HA: µ1 - µ2 ≠ 0, where µ1 is the population mean for population 1 and µ2 is the population mean for population 2. Also assume that the populations are normally distributed, the variances are known, and independent sampling is used. Which of the following expressions is the appropriate test statistic? tdf= d ---- sD/√n tdf= x1−x2 ------- √ s21/n1 +s22/n2 z.= x1−x2 ------- √ s21/n1 +s22/n2 tdf= x1−x2 -------- √ s2p (1/n1 +1/n2)
z.= x1−x2 ------- √ s21/n1 +s22/n2
