Exercise 16.45 used the example from How It Works 15.2 on the relation between age and how much people study. Recall that the mean for age is 21, and the standard deviation is 1.789. The mean for hours studied is 14.2, and the standard deviation is 5.582. The correlation coefficient is 0.49.
a. Calculate the regression equation.
b. Use the regression equation to predict the number of hours studied for a 17-year-old student and for a 22-year-old student.
c. Using the four pairs of scores that you have (age and predicted hours studied from part (b), and the predicted scores for a score of 0 and 1 from calculating the regression equation) create a graph that includes the regression line.
d. Why is it misleading to include young ages such as 0 and 5 on the graph?