Question 1 of 17
Q-Mart is interested in comparing its male and female customers. Q-Mart would like to know if the amount of money spent by its female charge customers differs, on average, from the amount spent by its male charge customers.
To answer this question, an analyst collected random samples of 25 female customers and 22 male customers.
Based on these samples, on average, the 25 women charge customers spent $102.23 and the 22 men charge customers spent $86.46.
Moreover, the sample standard deviation of the amount charged by the 25 women was $93.393, and the sample standard deviation of the amount charged by the 22 men was $59.695.
Using the procedure advocated by Bluman, at the 10% level of significance, is there sufficient evidence for Q-Mart to conclude that, on average, the amount spent by women charge customers differs from the amount spent by men charge customers.
A.Yes, the test value does not exceed the critical value
B.No, the p-value of this test is less than 0.10.
C.No, the test value does not exceed the critical value.
D.Yes, the p-value of this test is greater than 0.10 Reset Selection
Question 2 of 17
Two teams of workers assemble automobile engines at a manufacturing plant in Michigan.
A random sample of 145 assemblies from team 1 shows 15 unacceptable assemblies.
A similar random sample of 125 assemblies from team 2 shows 8 unacceptable assemblies.
Is there sufficient evidence to conclude, at the 10% significance level, that the two teams differ with respect to their proportions of unacceptable assemblies?
A.Yes, since the p-value is greater than 0.10
B.No, since the test value does not exceed the critical value
C.No, since the p-value is less than 0.10
D.No, since the test value exceeds the critical value Reset Selection
Question 3 of 17
Which of the following statements is true regarding the F - distribution?
A.It is a distribution of negative values
B.It is always skewed to the left
C.It typically appears in tests of equal proportions
D.none of the above Reset Selection
Part 2 of 8 -
Question 4 of 17
Data for a sample of 25 apartments in a particular neighborhood are provided in the worksheet Apartments in the Excel workbook Apartments.xlsx.
Using that data, find the estimated regression equation which can be used to estimate the monthly rent for apartments in this neighborhood using size as the predictor variable.
Apartments.xlsx
A.f$hat{y}= f$ 1.065 + 177.12(size)
B.f$hat{y}= f$ 197.12 + 2.065(size)
C.f$hat{y}= f$ 177.12 + 0.8500(size)
D. f$hat{y}= f$ 177.12 + 1.065(size) Reset Selection
Question 5 of 17
The city of Oakdale wishes to see if there is a linear relationship between the temperature and the amount of electricity used (in kilowatts).
Based on the data in the table below, is there a significant linear relationship between temperature and the amount of electricity used?
These data are also available in the worksheet temperature in the Excel workbook Temperature.xlsx.
Temperature.xlsx
Temperature (x)
73
78
85
98
93
81
76
105
Kilowatts (y)
680
760
910
1510
1170
837
600
1800
A.No, the sample correlation coefficient is equal to 0.981, which does not provide evidence of a significant linear relationship.
B.Yes, the sample correlation coefficient is equal to 0.878, which provides evidence of a significant linear relationship.
C.No, the sample correlation coefficient is equal to 0.098, which does not provide evidence of a significant linear relationship.
D.Yes, the sample correlation coefficient is equal to 0.981, which provides evidence of a significant linear relationship. Reset
Selection
Question 6 of 17
The regression line y' = -3 + 2.5 X has been fitted to the data points (28, 60), (20, 50), (10, 18), and (25, 55).
The sum of the squared residuals will be:
A.20.25
B.16.00
C.49.00
D.94.25 Reset Selection
Question 7 of 17
____________ is/are especially helpful in identifying outliers.
A.Scatterplots
B.Regression analysis
C.Linear regression
D.Normal curves Reset Selection
Question 8 of 17
If an estimated regression line has a Y-intercept of -7.5 and a slope of 2.5, then when X = 3, the actual value of Y is:
A.10
B.unknown
C.5
D.0 Reset Selection
Part 3 of 8 -
Question 9 of 17
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A survey of employees at a company finds that 32 of the 88 employees who drive to work were ever late during the past year, and 18 of the 64 employees who took public transportation were ever late during the past year.
At α = 0.10, is there a difference between the proportion of employees who drove who were ever late and the proportion of employees who took public transportation who were ever late?
Find the test value for the difference in the proportion of employees who were ever late for work in the past year.
Answer: Round your answer to two decimal places.
What is your decision for this test?
1. The test value is greater than the critical value of 1.960.
2. The test value is less than the critical value of 1.645.
3. The test value is greater than the critical value of 1.282.
4. The test value is less than the critical value of 1.960.
Answer: Enter only a 1, 2, 3 or 4 for your answer.
Part 4 of 8 -
Question 10 of 17
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
The marketing manager of a large supermarket chain would like to determine the effect of shelf space (in feet) on the weekly sales of international food (in hundreds of dollars). A random sample of 12 equal -sized stores is selected, with the following results:
Store Shelf Space(X) Weekly Sales(Y)
1 10 2.0
2 10 2.6
3 10 1.8
4 15 2.3
5 15 2.8
6 15 3.0
7 20 2.7
8 20 3.1
9 20 3.2
10 25 3.0
11 25 3.3
12 25 3.5
Using the equation of the regression line for these data, predict the average weekly sales (in hundreds of dollars) of international food for stores with 13 feet of shelf space for international food.
Place your answer, rounded to 3 decimal places , in the blank. Do not use a dollar sign. For example, 2.345 would be a legitimate entry.
Question 11 of 17
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A company has observed that there is a linear relationship between indirect labor expense (ILE) , in dollars, and direct labor hours (DLH). Data for direct labor hours and indirect labor expense for 18 months are given in the file ILE_and_DLH.xlsx
Treating ILE as the response variable, use regression to fit a straight line to all 18 data points.
Approximately what percentage of the variation in indirect labor expenses is explained by the regression model you derived?
Place your answer, rounded to 1 decimal place, in the blank. Do not use any stray punctuation marks or a percentage sign.
For example, 78.9 would be a legitimate entry.
Part 5 of 8 -
Question 12 of 17
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
An investor wants to compare the risks associated with two different stocks.
One way to measure the risk of a given stock is to measure the variation in the stock's daily price changes.
In an effort to test the claim that the variance in the daily stock price changes for stock 1 is different from the variance in the daily stock price changes for stock 2, the investor obtains a random sample of 21 daily price changes for stock 1 and 21 daily price changes for stock 2.
The summary statistics associated with these samples are: n1 = 21, s1 = .849, n2 = 21, s2 = .529.
If you follow Bluman's advice and place the larger variance in the numerator, what is the test value associated with this test of hypothesis?
Place your answer, rounded to 3 decimal places, in the blank.
For example, 3.456 would be a legitimate entry.
Question 13 of 17
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
Two teams of workers assemble automobile engines at a manufacturing plant in Michigan.
A random sample of 145 assemblies from team 1 shows 15 unacceptable assemblies.
A similar random sample of 125 assemblies from team 2 shows 8 unacceptable assemblies.
If you are interested in determining if there is sufficient evidence to conclude, at the 10% significance level, that the two teams differ with respect to their proportions of unacceptable assemblies, what is/are the critical value you would use to conduct such a test of hypothesis?
Place your answer, rounded to 2 decimal places, in the blank.
If there are two critical values, place only the positive value in the blank. For example, 2.34 would be a legitimate entry.
Part 6 of 8 -
Question 14 of 17
Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), "E" or "e" (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.
Complex numbers should be in the form (a + bi) where "a" and "b" need to have explicitly stated values.
For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.
A professor gives an exam for which there are two versions, A and B. Each student in the class is given one randomly selected version of the exam.
After the exam, the professor wishes to determine if there is a difference in the level of difficulty of the two versions by determining if there is a significant difference in the mean scores. Assume α = 0.05.
Version A
Version B
Sample size
45
65
Mean score
8.8
8.2
Sample variance
2.6
2.4
What is the test value for this hypothesis test?
Answer: Round your answer to two decimal places.
What is/are the critical value(s) for this hypothesis test? If there are two critical values, give only the positive value.
Answer: Round your answer to two decimal places.
What is the conclusion for this hypothesis test? Choose one.
1. There is not sufficient evidence to show that one version of the exam is more difficult than the other.
2. There is sufficient evidence to show that one version of the exam is more difficult than the other.
Answer: Enter only a 1 or 2 for your answer.
Part 7 of 8 -
Question 15 of 17
The number of degrees of freedom associated with the t-test, when the data are gathered from a paired samples experiment with 12 pairs, is 24.
True
False
Reset Selection
Part 8 of 8 -
Question 16 of 17
When the actual values y of a response variable and the corresponding predicted values y' are the same, the standard error of the estimate will be zero.
True
False
Reset Selection
Question 17 of 17
If there is no linear relationship between two variables X and Y, the coefficient of determination, R2, must be f$pm f$ 1.0.
True
False