The equation for the relationship between the amount of body fat (Y ) to 3 predictors, which are triceps skinfold thickness (X1), thigh circumference (X2), and midarm circumference (X3) is as follows:

Y= 117.062 + 4.295X1 -2.858X2 -2.142X2.


95.0% Confidence Interval for B is as follows:

Lower Bound Upper Bound
1 (Constant) -79.826 313.949
X1 -1.638 10.229
X2 -7.947 2.230
X3 -5.283 .998


(a) Connie is a 30-year-old female with
{ triceps skinfold thickness = 25
{ thigh circumference = 48
{ midarm circumference = 30

(b) Sally is a 34-year-old female with
{ triceps skinfold thickness = 30
{ thigh circumference = 56
{ midarm circumference = 32

The amount of body fat for Connie is calculated as follows:

Y= 117.062 + 4.295*25 -2.858*48 -2.142*30= 22.993
The amount of body fat for Connie and Sally is calculated as follows:

Y= 117.062 + 4.295*30-2.858*56 -2.142*32 = 17.32

Is it right?

What is the 95% prediction interval for body fat, for Connie
and Sally?