Question: You have landed nine sales contracts with an average price of $3,782 and a standard deviation of $1,290.
a. Identify a reasonable idealized population that this sample represents.
b. If the distribution of sales prices is heavily skewed, would it be appropriate to construct the usual two-sided 95% confidence interval? Why or why not?
c. Assume now that the distribution of sales prices is only slightly skewed and not too different from a normal distribution. Compute the usual two-sided 95% confidence interval, and interpret it carefully in terms of your long-term prospects at this job. Be sure to address both the useful information and the limitations of the confidence interval in this situation.
d. Find the two-sided 90% prediction interval for the sales price of the next contract you land, assuming that conditions will remain essentially unchanged.