Systolic blood pressure of randomly selected HMO patients was recorded on a particular Wednesday,with the results shown here.An ANOVA test was performed using these data. Degrees of freedom for the between-treatments sum of squares would be:
A) 3.
B) 19.
C) 17.
D) depends on α.

Question

Systolic blood pressure of randomly selected HMO patients was recorded on a particular Wednesday,with the results shown here.An ANOVA test was performed using these data.  Degrees of freedom for the between-treatments sum of squares would be:
A) 3. 
B) 19. 
C) 17. 
D) depends on α.

Quizplus · Accepted Answer

The degrees of freedom for the between-treatments sum of squares in an ANOVA test is equal to the number of groups minus 1. In this case, there are 4 groups (systolic blood pressure ranges), so the degrees of freedom for between-treatments sum of squares would be 4 - 1 = 3. Therefore, the correct choice is A. The choice does not depend on α.

Systolic Blood Pressure of Randomly Selected HMO Patients Was Recorded