1.Use a 5% significance level to perform the test that the population mean equals 150 versus the alternative hypothesis that it is less than this number. The sample size equals 100, the sample standard deviation equals 50, and the sample mean equals 145.

b) Repeat part a) whenx=140.

c) Repeat part a) when x=135.

d) Describe the effect on the test statistic when the sample mean decreases.