Using the Body Fat data set, fit a simple linear regression model for relating chest circumference (????) to abdomen circumference (????). Then,

(a) use the residuals to check the regression assumptions.

(b) provided the regression assumptions appear to be satisfied, test whether or not there is a linear relationship between chest circumference and abdomen circumference.

(c) estimate the mean chest circumference for an adult male having an abdomen circumference of 115 cm.

(d) compute a 95% confidence interval for the mean chest circumference for an adult male having an abdomen circumference of 115 cm.

(e) predict the chest circumference for an adult male having an abdomen circumference of 115 cm.

(f) compute a 95% prediction interval for the mean chest circumference for an adult male having an abdomen circumference of 115 cm.