Suppose That 9 Grades Are Drawn from a Normal Population

Essay

Suppose that 9 grades are drawn from a normal population whose standard deviation is 15.The observations are:
90
54
78
66
48
72
66
42
60
At 99% confidence,you want to determine whether the mean of the population from which this sample was taken is greater than 50.
a.State the null and alternative hypotheses.
b.Compute the value of the test statistic.
c.Compute the p-value.
d.Interpret the results.