Please show all the work.
1. Mr. James McWhinney, president of Daniel-James Financial Services, believes there is a relationship between the number of client contacts and the dollar amount of sales. To document this assertion, Mr. McWhinney gathered the following sample information. 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.
Number of Contacts, X Sales ($ thousands), Y
14 24
12 14
20 28
16 30
46 80
23 30
48 90
50 85
55 120
50 110
a. Determine the .95 confidence interval, in thousands of dollars, for the mean of all sales personnel who make 40 contacts.
b. Determine the .95 prediction interval, in thousands of dollars, for a particular salesperson who makes 40 contacts.