The Owner of Darkest Tans Unlimited in a Local Mall

Multiple Choice

The owner of Darkest Tans Unlimited in a local mall is forecasting this month's (October's) demand for the one new tanning booth based on the following historical data: $$\begin{array} { l l } \text { Month } & \text { Number of Visits } \\\hline \text { April } & 100 \\\text { May } & 140 \\\text { June } & 110 \\\text { July } & 150 \\\text { August } & 120 \\\text { September } & 160\end{array}$$ What is the monthly rate of change (slope) of the least squares trend line for these data?

A) 320
B) 102
C) 8
D) -.4
E) -8