We know that the national average on a particular reading test is 100 with a standard deviation of 10. We select a random sample of 100 students in our district and find that their mean score is 96. Are our students reading below average, or did we just happen to select a group of below-average students? Use a z test to decide.

a. z= -4.0. Do not reject the null hypothesis. The difference is not statistically significant. There is no evidence that our students are reading below average.

b. z= -1.4. Do not reject the null hypothesis. The difference is statistically significant. Our students are most likely below average in reading.

c. z= -1.4. Reject the null hypothesis. The difference is not statistically significant. There is no evidence that our students are reading below average.s

d. z= -4.0. Reject the null hypothesis. The difference is statistically significant. Our students are most likely below average in reading.