1,250 41 46 1,340 54 62 1,425 63 1.510 61 1,425 54 1.575 64 1,450 48 1,650 71…

1,250
41
46
1,340
54
62
1,425
63
1.510
61
1,425
54
1.575
64
1,450
48
1,650
71
1.Consider the data in Table P-3 where
weekly advertising, expenditures and
weekly sales.
a. Does a significant relationship exist between advertising expenditures and sales?
b. State the prediction equation.
c. Forecast sales for an advertising expenditure of $50.
d. What percentage of the variation in sales can be explained with the prediction equation?
e. State the amount of unexplained variation.
f. State the amount of total variation.
2.The times required to check out customers in a supermarket and the corresponding values of purchases are shown in Table P.4. Answer parts a, b, e, and f of Problem 3 using these data. Give a point forecast and a
interval forecast for
if
.