The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures students study habits and attitude toward school. Scores range from 0 to 200. The mean score for college students is about 115, and the standard deviation is about 30. A teacher suspects that the mean (u) for older students is higher than 115. She gives the SSHA to an SRS of 25 students who are at least 30 years old. Suppose we know that scores in the population of older students are Normally distributed with standard deviation .o=30
1. We seek evidence against the claim that u = 115. What is the sampling distribution of the mean score x of a sample of 25 students if the claim is true?u=115
A. Normal with mean u=115 and standard deviation 60.
B. Binomial with n = 25 and p = 60.
C. Approximately Normal with mean u=115 and standard deviation 6.
D. Normal with mean u=115 and standard deviation 6.