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.
H0: µ ≤220
H1: µ <220
(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.