Civil engineers collected data from one area of Wisconsin on the amount of salt (in tons) used to keep highways drivable during a snowstorm. The amount of salt for n = 20 storms are given: 1111 2115 1573 2813 2815 2126 854 3965 1819 776 1484 2056 784 779 1373 1237 1701 1957 246 1730
[a.] Does it appear that the conditions for a confidence interval on the population mean are satisfied? Justify why or why not (Hint: A Normal QQ plot would be useful here). We're going to make one anyway, but we should know whether it is appropriate to do so.
[b.] Report the summary statistics for a confidence interval on the population mean (though I am not interested in the calculations here).
[c.] Construct a 95% confidence interval for the population mean salt used per storm.
[d.] In 1-2 sentences, interpret the confidence interval in the context of the problem.