A random sample of 100 students is taken from a larger population of students in a multi-lecture course and the sample mean (average) of their final grades is found to be 62.25. Suppose it is known that the population standard deviation is 3.2. You wish to create a 92% confidence interval. Which of the following statements is most correct?

a.

The z/2 (found from R) used to calculate the 92% confidence interval is 2.053749.

b.

The z/2 (found from R) used to calculate the 92% confidence interval is 1.405072.

c.

The z/2 (found from R) used to calculate the 92% confidence interval is 1.750686.

d.

The z/2 (found from R) used to calculate the 92% confidence interval is 0.04.

2) A random sample of 100 students is taken from a larger population of students in a multi-lecture course and the sample mean (average) of their final grades is found to be 62.25. Suppose it is known that the population standard deviation is 3.2. You wish to determine whether the average grade for the population differs from 62. Use R to get the needed Z critical value and then create a 90% Z confidence interval for the average final grade for the population by hand. Choose the correct statement below.

a.The test is significant at the 10% significance level because 62 is inside the confidence interval you created.

b.The test is significant at the 10% significance level because 62 is outside the confidence interval you created.

c.The test is not significant at the 10% significance level because 62 is inside the confidence interval you created.

d.The test is not significant at the 10% significance level because 62.25 is inside the confidence interval you created.