A Realtor Collected the Following Data for a Random Sample

A realtor collected the following data for a random sample of ten homes that recently sold in her area.

$$\begin{array} { | c | c | c | } \hline \text { House } & \text { Asking Price } & \text { Days on Market } \\\hline \text { A } & \$ 114,500 & 29 \\\hline \text { B } & \$ 149,900 & 16 \\\hline \text { C } & \$ 154,700 & 59 \\\hline \text { D } & \$ 159,900 & 42 \\\hline \text { E } & \$ 160,000 & 72 \\\hline \text { F } & \$ 165,900 & 45 \\\hline \text { G } & \$ 169,700 & 12 \\\hline \text { H } & \$ 171,900 & 39 \\\hline \text { I } & \$ 175,000 & 81 \\\hline \text { J } & \$ 289,900 & 121 \\\hline\end{array}$$ a. Find a 90% confidence interval for the mean number of days on the market for all
houses listed at $150,000.
b. Suppose a house has just been listed at $150,000. Find a 90% prediction interval for the
number of days the house will be on the market before it sells.