Answer
r = 0.868. No, this measure is not useful since the relationship is not likely linear.
$R^{2} = 75.3\%$. This implies that 75.3% of the variation in the values can be explained on the basis of equation of least squares.
Work Step by Step
Calculate r in minitab from stats and then the correlation. Calculate $R^{2}$ from stats -> regression -> Fitted line plot.
