Chapter 13, Problem 61H

The F Distribution and the F-Ratio Use the following information to answer the next three exercises. Suppose a group is interested in determining whether

teenagers obtain their drivers licenses at approximately the same average age across the country. Suppose that the following

data are randomly collected from five teenagers in each region of the country. The numbers represent the age at which

teenagers obtained their drivers licenses.

Northeast	South	West	Central	East
16.3	16.9	16.4	16.2	17.1
16.1	16.5	16.5	16.6	17.2
16.4	16.4	16.6	16.5	16.6
16.5	16.2	16.1	16.4	16.8
x ¯=	-----	-----	-----	-----
S2 =	-----	-----	-----	-----

Table 13.20

H0: µ1 = µ2 = µ3 = µ4 = µ5

Ha: At least any two of the group means µ1, µ2, …, µ5 are not equal.

degrees of freedom − numerator: df(num) = _________