The Survey of Study Habits and Attitudes SSHA is a psycholog

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 115, and the standard deviation is about 30. A teacher suspects that the mean 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 = 30.

The P-value of the outcome is 0.0287. Is this outcome statistically significant at the = 0.05 level? At the = 0.01 level?

Solution

An outcome is significant if P < significance level.

Here, as P = 0.0287 < 0.05 but not less than 0.01, then:

It is significant at 0.05 level. [ANSWER]

It is not significant at 0.01 level. [ANSWER]