Statistics
The Survey of Study Habits and Attitudes (SSHA) is a psychological test that measures students' study habits and attitudes toward school. Scores range from 0 to 200. The mean score for college students is about 119, and the standard deviation is about 27.8. A teacher suspects that the mean μ for older students is higher than 119. She gives the SSHA to an SRS of 28 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 σ = 27.8. We seek evidence against the claim that μ = 119.
If the study shows that = 127.9 g/dl, what is the P-value (±0.0001) of this outcome?
Reply
Answers
The P-value is 0.007 (±0.0001). This means that the probability of observing a sample mean this far or further from the null hypothesis (μ = 119) is 0.007 (or less than 1%). This suggests that the null hypothesis is unlikely and should be rejected, providing evidence that the true mean for older students is higher than 119.
