Body fat. A medical research is trying to predict the percentage of body fat using the body mass index (BMI) (in kg/m2) in elderly males of about 60 years of age. It determines the model Fat% = 34.6144 - 0.1303 BMI with the following residuals plot for the relevant data.

a) Interpret the slope of the line in this context.

b) Interpret the y-intercept of the line in this context.

c) If an elderly male has a very high BMI reading of around 29 kg/m2, based on the model, would you expect his predicted percentage of body fat to be accurate, too low, or too high? Explain.

d) What is the predicted percentage of body if an elderly male has a BMI reading of 28.3kg/m2?

e) Based on the given model, if an elderly male has a BMI reading of 28.3kg/m2, what is that person’s actual percentage of body fat?

f) Do you think an elderly male should use this model?
Explain.
g) Would this model be more successful if the IBM readings were expressed in kg/cm2? Explain.

Transcribed Image Text:

Residuals 0.2 0.15 0.1 0.05 0 -0.05 BMI (kg/m) Residual Plot 27 27.5 . 28 28.5 29 29.5 -0.1 -0.15 -0.2 BMI (kg/m)