Suppose we claim that the average GPA for all students at a University (who have completed sixty hours) is less than 2.9. From a sample of 15 students, the average GPA is 2.85 with a standard deviation of 1.6. The GPA's are normally distributed and α = 0.05. Choose the appropriate decision rule below. (Chapter 7)
Reject H0 if t < -2.145
Reject H0 if z > 1.645
Reject H0 if z < -1.645
Reject H0 if t < -1.761
Reject H0 if t > 1.761