Construct Confidence Intervals for a Mean Response
-A Company Keeps $90 \%$

Construct Confidence Intervals for a Mean Response
-A company keeps extensive records on its new salespeople on the premise that sales should increase with experience. A random sample of seven new salespeople produced the data on experience and sales shown in the table. Construct a $90 \%$ confidence interval about the mean value of $y$ when $x = 5$ months.
$\begin{array}{c|c}\text { Months on Job } & \begin{array}{c}\text { Monthly Sales } \\\text { y (\$ thousands) }\end{array} \\\hline 2 & 2.4 \\4 & 7.0 \\8 & 11.3 \\12 & 15.0 \\1 & 0.8 \\5 & 3.7 \\9 & 12.0\end{array}$