The Following Are Partial Results of a Regression Analysis Involving $\alpha$

Essay

The following are partial 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.
a.At $\alpha$ = 0.05, test for the significance of the coefficient of advertising.
b.If the company uses $20,000 in advertisement and has 300 salespersons, what are the expected sales? (Give your answer in dollars.)