A random sample of 20 purchases showed the following amounts (in $)

39.05	2.73	32.92	47.51
37.91	34.35	64.48	51.96
56.95	81.58	47.80	11.72
21.57	40.83	38.24	32.98
75.16	74.3	47.54	65.62

An analyst wants to know if the mean purchase amount of all transactions is at least $40? Assume a significance level of 5%.

a) What is the null hypothesis?

b) Is the alternative hypothesis one-sided or two-sided?

c) What is the value of the test statistic?

d) What is the p-value of the test statistic?

e) What do you conclude at sigma = .05?