The head of institutional research at a university believed that the mean age of full-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 H0: µ = 27.4 years versus H1: µ < 27.4 years and obtained a P-value of 0.0019. He concluded that the mean age of full-time students did decline. Is there anything wrong with his research?