SCENARIO 9-9
The president of a university claimed that the entering class this year appeared to be larger than the entering class from previous years but their mean SAT score is lower than previous years.He took a sample of 20 of this year's entering students and found that their mean SAT score is 1,501 with a standard deviation of 53.The university's record indicates that the mean SAT score for entering students from previous years is 1,520.He wants to find out if his claim is supported by the evidence at a 5% level of significance.
-Referring to Scenario 9-9,if these data were used to perform a two-tail test,the p-value would be 0.1254.

Question

Quizplus · Accepted Answer

We can use a one-tail test because the president claimed that the mean SAT score is lower, not just different, than previous years. Therefore, the p-value for the one-tail test would be 0.0627, which is less than 0.05, indicating that we can reject the null hypothesis and support the president's claim. If we were to perform a two-tail test, the p-value would be twice the one-tail test, 0.1254, which is still greater than 0.05 and would not allow us to reject the null hypothesis. However, the correct test to use in this scenario is the one-tail test.

SCENARIO 9-9 The President of a University Claimed That the Entering Class