We present the results of a linear regression (yi = βο + β1χ1i + β2χ2i + εi) where y corresponds to the companies net profits, x1 to the within-store sales and x2 to the on-line sales (all in thousands USD)
Estimate Std. Error t-value p-value
(intercept) -20.2159 0.2643 *** 0.4409
x1 0.0855 0.0438 *** 0.0181
x2 0.1132 0.0385 *** 0.0220
a) Fill the empty parts of the table (indicated by asterisks). Given an interpretation of the β1 and β2 coefficients.
b) Comment the significance of the x1 and x2 variavles using the p-value.
c) Calculate the 95% confidence interval of the marginal effect of the on-line sales on the net profits (Assume a sample size of n =10 observations)
d) Predict the mean companies net profits if the within-store sales are 1 million and the on-line sales 500 thousands USD