It is widely believed that a person's level of fitness prior to undergoing corrective knee surgery is an important factor in the speed of rehabilitation following surgery.A study was undertaken with 24 randomly selected male subjects who were to undergo such surgery.The physical fitness status of each subject before the surgery was categorized as being below average (n = 8),average (n = 10),or above average (n = 6).Following surgery,the number of days spent in physical therapy by each patient until fully rehabilitated was determined.Examination of side-by-side boxplots indicated that it was reasonable to assume that the samples came from populations with equal standard deviations. The following ANOVA table was obtained.(Some entries have been replaced with _**.) The degrees of freedom associated with the ANOVA F test are ____________. A)F(3,21) B)F(2,22) C)F(2,23) D)F(2,21) E)F(3,20)

Question

Quizplus · Accepted Answer

The degrees of freedom associated with the ANOVA F test are (k-1, N-k), where k is the number of groups and N is the total sample size. In this case, there are three groups (below average, average, and above average) and a total sample size of 24. Therefore, the degrees of freedom are (2, 21). The correct answer is D.

It Is Widely Believed That a Person's Level of Fitness