Chapter 15
16. For the following data set For the following data set:
A. Calculate r and conduct a twotailed test of the null hypothesis ( =.05).
B. Specify the null and alternative hypotheses.
C. What is r crit ?
D. Reject or fail to reject the null hypothesis?
E. What percent of the variance of Y is accounted for by the variance of X ?
X Y
6 3
9 7
7 6
10 9
17. the following data set:
A.Calculate r and conduct a twotailed test of the null hypothesis ( =.05).
B. Specify the null and alternative hypotheses.
C. What is r crit ?
D Reject or fail to reject the null hypothesis?
E. What percent of the variance of Y is accounted for by the variance of X ?
x y
6 3
9 7
7 6
10 9
Chapter 16
18. Suppose a tax official learns that the slope for the regression line between the price of gas and the number of nonworkrelated miles driven by drivers to be 0.40. Interpret the likely relationship between gas prices and transportation activities like traveling for vacation.
19. Suppose a regression analysis of bivariate data gathered on the variables hours studied per week and GPA results in a regression equation as follows: Y p = 2.92 + 0.08( X 18). What would be our predicted GPA if we adopted each of the following study plans?
A. 10 hours a week.
B. 22 hours a week.
C. 30 hours a week.
20. following data set.
X Y
2 4
7 12
3 7
7 14
5 11
3 5
A. Calculate the slope of the regression line for predicting Y from X .
B. Establish the regression equation for predicting Y from X .
C. Calculate the corresponding s e using the computational formula.
21. Provide the requested statistics based on the following data set.
X Y
12 4
4 11
13 7
6 14
9 3
8 9
A. Calculate the slope of the regression line for predicting Y from X .
B. Establish the regression equation for predicting Y from X .
C. Calculate the corresponding s e using the computational formula.
Review 6
8. If a researcher wanted to predict charitable giving based on the level of political conservatism espoused by an individual, what statistical tool seems most appropriate? Why?
10. For the following bivariate data set, answer the following questions:
X Y
3 9
5 4
7 0
4 2
9 0
2 10
5 5
4 7
2 8
1 8
A. What is the correlation between X and Y ?
B. What is Y p if X =10?
C. Can the null hypothesis that X = Y be rejected?
11. Imagine the following data set is gathered regarding biological malefemale sibling pairs and their average daily time spent doing leisurely activities.
Male Female
3.9 4.2
1.6 1.9
2.9 1.6
3.5 2.3
3.3 2.1
4.9 4.0
5.5 3.5
4.4 5.3
3.7 2.1
3.5 2.0
A. Test the null that there is no difference between biological males and biological females regarding daily leisure time.
B. Test the null that there is no relationship for time spent in leisure between siblings.
C. What if we know our friend, Jimmy, spends two hours playing video games every day in an otherwise highly structured life, how many hours might Jenny, his sibling, have to engage in a leisurely activity?
12.Suppose we are interested in the relationship between the number of siblings a child has and the age at which they learn to walk. We ask mothers of seven twoyearolds how many older siblings the child has and the age the child began to walk. Data are listed below. Answer the questions that follow.
Number of siblings Age of walking (months)
1 16.0
2 8.5
0 16.5
3 10.0
1 11.0
2 10.0
3 9.0
A. Is there evidence of a relationship?
B. If so, how strong is the relationship?
C. Suppose a new child enters into the study with five older siblings. When might they begin to walk?
D. How confident are we in our prediction?
