The Following Is Part of the Results of a Regression

Essay

The following is part of the results of a regression analysis involving sales Y in millions of dollars), advertising expenditures X1 in thousands of dollars), and number of salespeople X2) for a corporation. The regression was performed on a sample of 10 observations.
$\begin{array}{lr}&\text { Coefilicient }&\text { Standard Error }\\\text { Intercept } & 40.00 & 7.00 \\X_{1} & 8.00 & 2.50 \\X_{2} & 6.00 & 3.00\end{array}$
a. If the company uses $40,000 in advertisement and has 30 salespersons, what are the expected sales? Give your answer in dollars.
b. At α = 0.05, test for the significance of the coefficient of advertising.
c. At α = 0.05, test for the significance of the coefficient of the number of salespeople.