Chapter 10, Problem 4E

For Exercises 1–4, answer the questions: (a) Is this a one- or two-tailed test? (b) What is the decision rule? (c) What is the value of the test statistic? (d) What is your decision regarding H₀? (e) What is the p-value? Interpret it.

4. A sample of 64 observations is selected from a normal population. The sample mean is 215, and the population standard deviation is 15. Conduct the following test of hypothesis using the .025 significance level.

$\begin{array}{c}{H}_0:\text{μ}\ge \text{220}\\ H_1:\text{μ}<\text{220}\end{array}$