Refer to Case Study 10.2, in which students reported their ideal and actual weights. When males and females are not separated, the regres­sion equation is ideal 58.0 10.9 actual
a. Draw the line for this equation and the line for the equation ideal 5 actual on the same graph. Comment on the graph as compared to those shown in Figures 10.9 and 10.10, in terms of how the regression line differs from the line where ideal and actual weights are the same.
b. Calculate the ideal weight based on the combined regression equation and the ideal weight based on separate equations, for individuals whose actual weight is 150 pounds. Recall that the separate equations were For women: ideal 5 43.9 1 0.6 actual For men: ideal 552.5 10.7 actual
c. Comment on the conclusion you would make about individuals weighing 150 pounds if you used the combined equation compared with the conclusion you would make if you used the separate equations.