Exercise 11.1 described a regression model between percent of body fat (%BF) as measured by immersion and BMI from a study on 250 male subjects. The researchers also measured 13 physical characteristics of each man, including his age (yrs), height (in), and waist size (in). A regression of percent of body fat with both height and waist as predictors shows the following computer output:

Residual standard error: 4.46 on 247 degrees of freedom Multiple R-squared: 0.7132, Adjusted R-squared: 0.7109 F-statistic: 307.1 on 2 and 247 DF, p-value: < 2.2e-16

(a) Write out the regression model if

and

(b) Verify that the model found from technology is correct to at least 2 decimal places.

(c) What is the predicted body fat of a man who is 6-ft tall with a 34-in waist?

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Estimate std. Error 7.68611 0.10994 0.07158 t-value Pr(>|t|) 0.687 (Intercept) Height Waist -3.10088 -0.60154 1.77309 -0.403 -5.472 24.770 1.09e-07 < 2e-16 -4.0042E-2 -4.1679E–2 6.0774E-4 -7.3875E-5 2.5766E-4 2.9705 (X'X)- =|-0.04004 -0.00417 -7.3875E–5