Solve

1 Consider an estimated linear regression model with a response Y and four predictors X1, X2, X3,and X4, based on a random sample of 25 sales agents of medical supplies in 3 regions of the province. Y is annual sales in 1000$, X1 in 100$, X2 in 100$, X3 in %, and X4 in 1000$. The regression results are given below. Coefficients Standard Error Find the lower limit of the change in the mean response for a Intercept -593.53745 259.19585 unit change in the X4 with a 98% confidence level, assuming X1 2.51314 0.31428 that the other predictors remain unchanged over the period. X2 1.90595 0.74239 X3 2.65101 4.63566 X4 -0.12073 0.37181