Problem 4-13

Students in a management science class have just received their grades on the first test. The instructor has provided information about the first test grades in some previous classes as well as the final average for the same students. Some of those grades have been sampled and are as follows.

Student 1 2 3 4 5 6 7 8 9

First test grade 98 77 88 80 96 61 66 95 69

Final average 93 78 84 73 84 64 64 95 76

Develop a regression model that can be used to predict the final average in the course based on the first test grade.

Predict the final average of a student who made an 83 on the first test.

Give the values of r and r2 for this model. Interpret the value of r2 in the context of this problem.

This must be done in excel and formulas must be present.

Problem 4-14

Using the data in 4-13, test to see if there is a statistically significant relationship between the grade on the first test and the final average at the 0.05 level of significance. Use the formulas in this chapter and appendix D. (See end of document for Appendix D).

This must be done in Excel and formulas must be present.

Problem 4-15

Using computer software, find the least-squares regression line for the data in problem 4-13. Based on the F-test, is there a statistically significant relationship between the first test grade and the final average in the course?

This must be done in Excel and formulas must be present.

Problem 4-19

Bus and subway ridership in Washington DC, during the summer months is believed to be heavily tied to the number of tourists visiting the city. During the past 12 years, the following data have been obtained:

Year Number of tourists Ridership (1,000,000s) (1,000,000s)

1 7 15

2 2 10

3 6 13

4 4 15

5 14 25

6 15 27

7 16 24

8 12 20

9 14 27

10 20 44

11 15 34

12 7 17

Plot these data and determine whether a linear model is reasonable.

Develop a regression model.

What is expected ridership if 10 million tourists visit the city?

This must be done in Excel and formulas must be present.