Suppose that IQs of adult Canadians follow a normal distribution with a standard deviation of 15. A random sample of 25 adult Canadians has a mean IQ of 112.

a. The margin of error for a 93% confidence interval for the true mean IQ of adult Canadians is?

b. At the 7% level of significance, we would like to test whether the true mean IQ of all adult Canadians is different from 115. What is the P-value for the appropriate test of significance?

c. Suppose we had instead used the critical value method to conduct the test in the previous question. We would reject H0 if?

d. If the margin of error in a is used to construct a confidence interval, could the interval have been used to conduct the hypothesis test in Question b?n