For a sample of 8 employees, a personnel director has collected the following data on ownership of company stock versus years with the firm.
x = Years y = Shares
6....... 300
12........ 408
14........ 560
6....... 252
9....... 288
13........ 650
15........ 630
9....... 522
a. Determine the least-squares regression line and interpret its slope.
b. For an employee who has been with the firm 10 years, what is the predicted number of shares of stock owned?