Burning calories with exercise. Table 28.13 provides data on speed and calories burned per hour for a 175- pound male using two different treadmills (a Cybex and a LifeFitness) at inclines of 0%, 2%, and 4%
(a) Create a scatterplot of calories against miles per hour using six different plotting symbols, one for each combination of incline level and machine.
(b) Create an indicator variable for brand of treadmill, say Treadmill =1 for Cybex and Treadmill = 0 for LifeFitness. Fit a multiple regression model to predict Calories from Mph, IndSlow, NoIncline, 2%Incline, and Treadmill.
(c) Does the model provide a good fit for these data? Explain.
(d) Is there a significant difference in the relationship between calories and speed for the two different treadmills?
