Consider a study investigating the relationship between husband's height and wife's height in young couples. The mean height of wives in their twenties participating in the study is about 60.4 inches, and the standard deviation is about 3.4 inches. The mean height of husbands the same age is about 70.1 inches, with a standard deviation of about 2.8 inches. Suppose that the correlation between the heights of husbands and wives is about r = 0.61.

a) (4 pts) What are the slope and intercept of the regression line of the husband's height on the wife's height in young couples? Interpret the slope in the context of the problem.

b) (4 pts) Draw a graph (by hand, do not use Python) of this regression line for heights of wives between 55 and 75 inches. Predict the height of the husband of a woman who is 68 inches tall and plot the wife's height and predicted husband's height on your graph.

c) (4 pts) What percentage of the variation in husband's height is explained by the straightline relationship with wife's height? d) (4 pts) Based on the result in part c), do you expect the prediction made in part b) to be accurate? Why or why not?