a. Determine the standard error of estimate.

b. Suppose a large sample is selected (instead of just 10). About 95 percent of the predictions regarding sales would occur between what two values?

Number of              Sales                 Number of                Sales
Contacts,          ($ thousands),          Contacts,             ($ thousands),
X                              Y                         X                           Y
14                             24                     23                           30
12                             14                     48                           90
20                             28                     50                           85
16                             30                     55                           120
46                             80                     50                           110