## Functions Modeling Change: A Preparation for Calculus, 5th Edition

This value of $r$ is unreasonable.
$r=-0.9$ means that the data is strongly correlated to a downward sloping line, since $-0.9$ is close to $-1$. However, the data correlation isn't strong, since the deviation of the points from the line is large. Therefore, the $r$ estimate isn't great.