Math 302 Quiz 5 2019 (Already Graded A+)
Question 1 of 17 1.0/ 1.0 Points
A researcher hypothesizes that the variation in the amount of

... [Show More] money spent on business dinners is greater than the variation of the amount of money spent on lunches. The variance of nine business dinners was $6.12 and the variance of 12 business lunches was $0.87. What is the test value?
A.3.10
B.9.61
C.7.03
D.49.50
Answer Key:
Question 2 of 17 1.0/ 1.0 Points
A pharmaceutical company is testing the effectiveness of a new drug for lowering cholesterol. As part of this trial, they wish to determine whether there is a difference between the effectiveness for women and for men. Assume α = 0.05. What is the test value?
Women Men
Sample size 50 80
Mean effect 7 6.95
Sample variance 3 4
A.t = 0.151
B.z = 0.455
C.t = 3.252
D.z = 0.081
Answer Key:
Question 3 of 17 1.0/ 1.0 Points
Members of the general adult population volunteer an average of 4.2 hours per week. A random sample of 20 female college students and 18 male college students produced the results given in the table below. At the .01 level of significance, is there sufficient evidence to conclude that a difference exists between the mean number of volunteer hours per week for male and female college students?
Females Males
Sample size 20 18
Sample mean 3.8 2.5
Sample variance 3.5 2.2
A.No, because the test value 2.38 is greater than the critical value
B.No, because the test value 2.38 does not exceed the critical value
C.No, because the test value 2.90 is greater than the critical value
D.Yes, because the test value 2.90 is greater than the critical value
Answer Key:
Part 2 of 8 - 4.0/ 5.0 Points
Question 4 of 17 1.0/ 1.0 Points
In choosing the “best-fitting” line through a set of points in linear regression, we choose the one with the:
A.smallest number of outliers
B.smallest sum of squared residuals
C.largest number of points on the line
D.largest sum of squared residuals
Answer Key:
Question 5 of 17 1.0/ 1.0 Points
A single variable X can explain a large percentage of the variation in some other variable Y when the two variables are:
A.highly correlated
B.mutually exclusive
C.directly related
D.inversely related
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Question 6 of 17 1.0/ 1.0 Points
Outliers are observations that
A.render the study useless
B.lie outside the typical pattern of points
C.disrupt the entire linear trend
D.lie outside the sample
Answer Key:
Question 7 of 17 1.0/ 1.0 Points
Correlation is a summary measure that indicates:
A.the strength of the linear relationship between pairs of variables
B.the rate of change in Y for a one unit change in X
C.the magnitude of difference between two variables
D.a curved relationship among the variables
Answer Key:
Question 8 of 17 0.0/ 1.0 Points
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.5
B.unknown
C.10
D.0
Answer Key:
Part 3 of 8 - 2.0/ 2.0 Points
Question 9 of 17 2.0/ 2.0 Points
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 field researcher is gathering data on the trunk diameters of mature pine and spruce trees in a certain area. The following are the results of his random sampling. Can he conclude, at the 0.10 level of significance, that the average trunk diameter of a pine tree is greater than the average diameter of a spruce tree?
Pine trees Spruce trees
Sample size 30 35
Mean trunk diameter (cm) 45 39
Sample variance 120 140
What is the test value for this hypothesis test?
Test value: 2.121 Round your answer to three decimal places.
What is the critical value?
Critical value: 1.311 Round your answer to three decimal places.
Answer Key:
Part 4 of 8 - 2.0/ 2.0 Points
Question 10 of 17 1.0/ 1.0 Points
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
Find the equation of the regression line for these data. What is the value of the standard error of the estimate? Place your answer, rounded to 3 decimal places, in the blank. Do not use a dollar sign. For example, 0.345 would be a legitimate entry. 0.308
Answer Key:
Question 11 of 17 1.0/ 1.0 Points
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.
Using your estimated regression output, predict the indirect labor expenses for a month in which the company has 31 direct labor hours.
Place your answer, rounded to 1 decimal place, in the blank. Do not use any stray punctuation marks or a dollar sign. For example, 458.9 would be a legitimate entry. 525.4
Answer Key:
Part 5 of 8 - 0.0/ 2.0 Points
Question 12 of 17 0.0/ 1.0 Points
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. 1.15
Answer Key:
Question 13 of 17 0.0/ 1.0 Points
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.
Are America's top chief executive officers (CEOs) really worth all that money? One way to answer this question is to look at the annual company percentage increase in revenue versus the CEO's annual percentage salary increase in that same company. Suppose that a random sample of companies yielded the following data:
percent change for corporation 15 12 3 12 28 6 8 2
percent change for CEO 6 17 -4 12 32 -1 7 2
Do these data indicate that the population mean percentage increase in corporate revenue is greater than the population mean percentage increase in CEO salary? Use a 5% level of significance. What is the critical value that you would use to conduct this test of hypothesis? Place your answer, rounded to 3 decimal places, in the blank. For example, 2.345 would be a legitimate entry. 1.010
Answer Key:
Part 6 of 8 - 2.0/ 3.0 Points
Question 14 of 17 2.0/ 3.0 Points
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.
Researchers conducted an experiment to measure the effect of a drug on improving the quality of sleep as determined by how many more minutes of REM sleep were measured for each participant. One group of participants were given the experimental drug; the other (control) group was given a placebo. Does the evidence indicate that the drug improved the amount of REM sleep at a 0.01 level of significance? Answer each of the following parts.
Experimental group Control group
sample size 35 50
mean sleep improvement 12.8 9.1
sample variance 56.3 61.2
What is the test value for this hypothesis test?
Answer:
Round your answer to two decimal places.
What is the P-value for this hypothesis test?
Answer:
What is the conclusion of this hypothesis test? Choose one.
1. There is sufficient evidence to show that the experimental drug improved the quality of sleep.
2. There is not sufficient evidence to show that the experimental drug improved the quality of sleep.
3. There is sufficient evidence to show that the quality of sleep is different for the experimental drug than for the control drug.
4. There is not sufficient evidence to show that the control drug decreased the quality of sleep.
Answer:
Answer Key:
Feedback: This is a t-test of independent samples. Use the formula on page 480 to compute the t test value:
This is a right-tail test with test value t = 2.198423 and df = 34 (using the smaller sample size). The P-value is 0.0174 using TDIST(2.1983423,34,1) or the Critical Values workbook.
Because the P-value is greater than alpha (0.01), there is not sufficient evidence to show that the experimental drug improved the quality of sleep.
Part 7 of 8 - 1.0/ 1.0 Points
Question 15 of 17 1.0/ 1.0 Points
In conducting hypothesis testing for difference between two means when samples are dependent (paired samples), the variable under consideration is ; the sample mean difference between the pairs.
True
False
Answer Key:
Part 8 of 8 - 2.0/ 2.0 Points
Question 16 of 17 1.0/ 1.0 Points
In a simple regression analysis, if the standard error of estimate sest = 15 and the number of observations n = 10, then the sum of the residuals squared must be 120.
True
False
Answer Key:
Question 17 of 17 1.0/ 1.0 Points
To help explain or predict the response variable in every regression study, we use one or more explanatory variables. These variables are also called predictor variables or independent variables.
True
False
Answer Key: [Show Less]