Suppose that 9 observations are drawn from a normal population whose standard deviation is 2. The observations are: 15, 9, 13, 11, 8, 15, 11, 7, and 10. At 95% confidence, you want to determine whether the mean of the population from which this sample was taken is significantly different from 10.

a.	State the null and alternative hypotheses.
b.	Compute the value of the test statistic.
c.	Compute the p-value.
d.	Interpret the results.