Question

The head of Institutional research at a university believed that the mean age of ful-time students was declining. In 1995, the mean age of a full-time student was known to be 27.4 years. After looking at the enrollment records of all 4934 full-time students in the current semester, he found that the mean age was 27.1 years, with a standard deviation of 7.3 years. He conducted a hypothesis of Hou-27.4 years versus H u <27.4 years and obtained a P.value of 0.0020. He concluded that the mean age of full-time students did decline. Is there anything wrong with his research? Choose the correct answer below. or below. O A. Yes, a P value only indicates the likelihood of getting a result as extreme or more extreme as the one found, the head of institutional research needs to include a confidence level. O B . Yes, the head of institutional research has access to the entire population, Inference is unnecessary. He can say with 100% confidence that the mean age has decreased. O C. Yes, the head of institutional research stated the hypotheses incorrectly, a left-tailed hypothesis test was conducted instead of a two-tailed test. OD. No, the hypothesis test was conducted correctly, and the correct conclusion was made

Answer 1

B. Yes, the head of institutional research has access to the entire population, inference is unnecessary. He can say with 100% confidence that the mean age has decreased.