The data in Enroll.sav, available on the publisher’s website for this text at the address http://www.pearsonhighered.com/stern2e, show yearly fall undergraduate enrollments between 1961 and 1989 reported by the Office of Institutional Research at the University of New Mexico. The other variables show % unemployment for New Mexico (Unemp), number of students graduating that spring from high school (Hgrad), and the per capita income in Albuquerque in 1961 dollars (Income).
1. Use the variables Unemp, Hgrad, and Income in a linear regression analysis to predict fall undergraduate enrollment. What is the equation? What is the value of R2 for the equation?
2 What statistic could a person use to determine how much error in predicting student enrollment would have occurred if the equation specified in question 1 had been used between 1961 and 1989?
3. An administrator suggests that enrollments increase by some uniform amount each year and that it is not at all helpful to take into account any other variables included in the data file in order to optimally predict fall undergraduate enrollments. How can this idea be tested? Is there sufficient evidence to reject the administrator’s idea?
