Chapter 14, Problem 21RP

Graduation Rates. Graduation rate—the percentage of entering freshmen attending full time and graduating within 5 years—and what influences it is a concern in U.S. colleges and universities.

U.S. News and World Report's “College Guide” provides data on graduation rates for colleges and universities as a function of the percentage of freshmen in the top 10% of their high school class, total spending per student, and student-to-faculty ratio. A random sample of 10 universities gave the following data on student-to-faculty ratio (S/F ratio) and graduation rate (Grad rate).

1. a. Draw a scatterplot of the data.
2. b. Is finding a regression line for the data reasonable? Explain your answer.
3. c. Determine the regression equation for the data, and draw its graph on the scatterplot you drew in part (a).
4. d. Describe the apparent relationship between student-to-faculty ratio and graduation rate.
5. e. What does the slope of the regression line represent in terms of student-to-faculty ratio and graduation rate?
6. f. Use the regression equation to predict the graduation rate of a university having a student-to-faculty ratio of 17.
7. g. Identify outliers and potential influential observations.