11.1 A study was conducted at Virginia Tech to determine if certain static arm-strength measures have an influence on the “dynamic lift” characteristics of an individual. Twenty-five individuals were subjected to strength tests and then were asked to perform a weightlifting test in which weight was dynamically lifted overhead.

The data are given here.

Arm Dynamic Individual Strength, x Lift, y 123456789 10 11 12 17.3 19.3 19.5 19.7 22.9 23.1 26.4 26.8 27.6 28.1 28.2 28.7 71.7 48.3 88.3 75.0 91.7 100.0 73.3 65.0 75.0 88.3 68.3 96.7 13 14 15 16 17 18 19 20 21 22 23 24 25 29.0 29.6 29.9 29.9 30.3 31.3 36.0 39.5 40.4 44.3 44.6 50.4 55.9 76.7 78.3 60.0 71.7 85.0 85.0 88.3 100.0 100.0 100.0 91.7 100.0 71.7

(a) Estimate β0 and β1 for the linear regression curve

μY |x = β0 + β1x.

(b) Find a point estimate of μY |30 .

(c) Plot the residuals versus the x’s (arm strength).

Comment.