Interpreting Confidence Intervals (3)• Example 6.2.2– A physical therapist wished to estimate, with 99%confidence, the mean maximal strength of a particularmuscle in a certain group of individuals. He is willing toassume that strength scores are approximately normallydistributed with a variance of 144. A sample of 15 subjectswho participated in the experiment yielded a mean of 84.3.