A researcher investigating the determinants of hamburger sales in a particular restaurant in the US fits the following model:

Sales_? = ?_? + ?_?Price_? + ?_?Advert_? + e_?

The variables are defined as below.

Sales	Monthly sales revenue of hamburgers sales in thousands of dollars
Price	Price of hamburgers in dollars
Advert	Advertising expenditure in dollars

Question:

Determine whether the estimated coefficients are statistically significant at the 1% level of significance

Variable | Obs Mean Std. Dev. Min Max sales 75 77. 37467 6. 488537 62 . 4 91.2 price 75 5. 6872 . 518432 4. 83 6. 49 advert | 75 1. 844 . 8316769 5 3.1 regress sales price advert Source | SS df MS Number of obs 75 F (2, 72) 29.25 Model | 1396.53893 2 698 .269465 Prob > F 0 . 0000 Residual | 1718 . 94294 72 23. 8742075 R-squared 0. 4483 Adj R-squared 0. 4329 Total | 3115. 48187 74 42. 1011063 Root MSE 4. 8861 sales | Coef. Std. Err. t P>It/ [95% Conf. Interval] price | -7. 907854 1. 095993 -7.22 0. 000 -10. 09268 -5. 723032 advert | 1. 862584 . 6831955 2.73 0. 008 500659 3. 22451 cons 118 .9136 6. 351638 18.72 0 . 000 106 .2519 131.5754 predict u, residuals sktest u Skewness/Kurtosis tests for Normality ---- joint - Variable | Obs Pr (Skewness) Pr (Kurtosis) adj chi2 (2) Prob>chi2 75 0. 7845 0. 4974 0 . 55 0. 7614 estat vif Variable | VIF 1/VIF advert 1.00 0 . 999305 price 1.00 0. 999305 Mean VIF | 1.00 estat ovtest Ramsey RESET test using powers of the fitted values of sales Ho : model has no omitted variables F (3, 69) = 3. 15 Prob > F = 0 . 0303