1. Accountant at the firm Walker and Walker believed that several traveling executives submit unusually high travel vouchers when they return from business trips. The accountant took a sample of 200 vouchers submitted from the past year; they then developed the following multiple regression equation relating expected travel cost {Y} to number of days on the road {XI} and distance traveled (X2) in miles: '2 = $90.00 + $48.50?1 + $0.40? 2 The coefficient of correlation computed was 0.58. (a) If Thomas Williams returns from a 300-mile trip that took him out of town for 5 days, what is the expected amount that he should claim as expenses? (b) Williams submitted a reimbursement request for $585; what should the accountant do? (c) Comment on the validity of this model. What is the adjusted r squared? How much variability in the travel cost is captured by the current model? Should any other variables be included? Which ones? Why? 2. A sample of nine public universities and nine private universities was taken. The total cost for the year (including room and board} and the median SAT score {maximum total is 2400} at each school were recorded. It was felt that schools with higher median SAT scores would have a better reputation and would charge more tuition as a result of that. The data are in the following table. Use regression to help answer the following questions based on this sample data. Do schools with higher SAT scores charge more in tuition and fees? Are private schools more expensive than public schools when SAT scores are taken into consideration? Discuss how accurate you believe these results are using information related to the regression models. CATEGORY TOTAL COST (5;) MEDIAN SAT Public 21,700 1990 Public 15,600 1620 Public 16,900 1810 Public 15,400 1540 Public 23,100 1540 Public 21,400 1500 Public 16,500 1560 Public 23,500 1890 Public 20,200 1520 Private 30,400 1630