Answer
$R^2=0.7605=76.05$%
76.05% of the variation of the 28-day strength is explained by the model found in part (b).
$R^2_{adj}=0.7006=70.06$%
It adjusts the value of $R^2$, given the size of the sample, n, and the number of explanatory variables, k.
Work Step by Step
See the results in MINITAB, part (b).
$R^2=0.7605=76.05$%
$R^2_{adj}=1-(\frac{n-1}{n-k-1})(1-R^2)=1-(\frac{11-1}{11-2-1})(1-0.7605)=0.7006$
