Exhibit 13.5 A police chief wants to determine if crime rates are different for four different areas of the city (East(1),West(2),North(3),and South(4)sides),and obtains data on the number of crimes per day in each area.The one-way ANOVA table and Tukey's confidence intervals are shown below. Refer to Exhibit 13.5.The degrees of freedom for the hypothesis test are:
A)4,20
B)3,23
C)3,20
D)4,23

Question

Exhibit 13.5 A police chief wants to determine if crime rates are different for four different areas of the city (East(1),West(2),North(3),and South(4)sides),and obtains data on the number of crimes per day in each area.The one-way ANOVA table and Tukey's confidence intervals are shown below.   Refer to Exhibit 13.5.The degrees of freedom for the hypothesis test are:
A)4,20 
B)3,23 
C)3,20 
D)4,23

Quizplus · Accepted Answer

The degrees of freedom for the hypothesis test in a one-way ANOVA are (k-1) and (n-k), where k is the number of groups and n is the total sample size. In this case, k=4 and n=24, so the degrees of freedom are (4-1) and (24-4), which equals 3 and 20 respectively. Therefore, the correct answer is C.