11. An accountant at the firm Bragg and Bragg believed that several traveling executives were submitting unusually hihg travel vouchers when they returned from business trips. First, she took a sample of 300 vouchers submitted from past year.Then she developed the following multiple regression equation relating expected travel cost (y) to number of days on the rod (x1) and distance traveled (x2) in miles:

y = $90.00 + $48.50x1 + $0.40x2

The coefficient of correlation computed was .68.

a. If Bill Tomlinson returns from a 300-mile trip that took him out of town for 5 days, what is the expected amount he should claim as expenses (use the regression equation to predict this value)?

b. Tomlinson submitted a reimbursement request for $685. What should the accountant do?

c. Should any other variables be included. Which ones? Why?