Mr. James McWhinney, manager of Daniel James Financial Services, believes there is a relationship in the number of customer contacts and the dollar amount of sales. To document this assertion, Mr. McWhinney gathered the following sample data. The X column indicates the number of client contacts last month, and the Y column shows the value of sales ($ thousands) last month for each client sampled.
X Y
# of contacts Sales in $thousands
14 24
12 14
20 28
16 30
46 80
23 30
48 90
50 85
55 120
50 110

Determine the regression equation.
Determine the estimated sales if 40 contacts are made.
Determine the standard error of estimate.
Suppose a larger sample is selected (instead of just 10). About 95 percent of the predictions
regarding sales would occur between what two values? Make sure you show your work.