Pop-Up Coffee Vendors Have Been Popular in the City of Adelaide

Essay

Pop-up coffee vendors have been popular in the city of Adelaide in 2013. A vendor is interested in knowing how temperature (in degrees Celsius) impacts daily hot coffee sales revenue (in $00's).
A random sample of 6 days was taken, with the daily hot coffee sales revenue and the corresponding temperature of that day noted. Excel regression output given below. $\begin{array}{|c|c|}\hline \text { Coffee sales revenue } & \text { Temperature } \\\hline 6.50 & 25 \\\hline 10.00 & 17 \\\hline 5.50 & 30 \\\hline 4.50 & 35 \\\hline 3.50 & 40 \\\hline 28.00 & 9 \\\hline\end{array}$
(a) Estimate daily hot coffee sales revenue on a day of 38 degrees Celsius.
(b) Is your prediction in part (a) reasonable?