A Confidence Interval When the Population Standard Deviation Is Unknown and Small Sample Case · Exercise 27

Suppose that a committee is studying whether or not there is waste of time in our judicial system. It is interested in the mean amount of time individuals waste at the courthouse waiting to be called for jury duty. The committee randomly surveyed 81 people who recently served as jurors. The sample mean wait time was eight hours with a sample standard deviation of four hours.

(a) (a) $\bar{x}$ = __________
(b) $s_x$ = __________
(c) n = __________
(d) n – 1 = __________
(b) Define the random variables $X$ and $\bar{X}$ in words.
(c) Which distribution should you use for this problem? Explain your choice.
(d) Construct a 95% confidence interval for the population mean time wasted.
(a) State the confidence interval.
(b) Sketch the graph.
(e) Explain in a complete sentence what the confidence interval means.

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Introductory Business Statistics 2e · §8.2 A Confidence Interval When the Population Standard Deviation Is Unknown and Small Sample Case · Exercise 27