A Simple Random Sample of Ten Firms Was Asked How

Essay

A simple random sample of ten firms was asked how much money (in thousands of dollars) they spent on employee training programs this year and how much they plan to spend on these programs next year. The data are shown below. $$\begin{array} { l r r r r r r r r r r } \text { Firm } & 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 \\\text { This year } & 25 & 31 & 12 & 15 & 21 & 36 & 18 & 5 & 9 & 17 \\\text { Next year } & 21 & 30 & 18 & 20 & 22 & 36 & 20 & 10 & 8 & 15\end{array}$$ Assume that the populations of amount spent on employee training programs are normally distributed.
a. Estimate with 95% confidence the mean difference.
b. Briefly explain what the interval estimate in part a. tells you.