The Atlantic Elevator Company conducted a study to examine the relationship between the total weight of passengers on an elevator (x, in pounds) and the total energy (y, in kW) required to lift the...

The Atlantic Elevator Company conducted a study to examine the relationship between the total weight of passengers on an elevator (x, in pounds) and the total energy (y, in kW) required to lift the passengers one floor in an office building. A simple linear regression analysis was conducted, and the following residuals were obtained.

a. Carefully sketch a normal probability plot for the residuals.

 b. Is there any evidence that the random error terms are not normal? Justify your answer.