Question

A grassroots group opposed to a proposed increase in the gas tax claimed that the increase would hurt working-class people the most, since they commute the farthest to work. Suppose that the group randomly surveyed 24 individuals and asked them their daily one-way commuting mileage. The results are below. Using a 5% significance level, test the hypothesis that the three mean commuting mileages are the same. (Let 1 = Working-class, 2 = Professional (middle incomes), and 3 = Professional (wealthy).)

Working-class	Professional (middle incomes)	Professional (wealthy)
17.3	16.4	8.4
25.9	16.7	6.0
48.6	21.5	3.9
8.7	6.6	12.5
64.7	9.1	10.6
46.2	1.8	28.1
18.7	5.6	14.8
50.7	13.4	8.5

A. Enter an exact number as an integer, fraction, or decimal.
df(num) =
B. Enter an exact number as an integer, fraction, or decimal.
df(denom) =
C. What is the test statistic? (Round your answer to two decimal places.)
D. What is the p-value? (Round your answer to four decimal places.)

F. What is the alpha? (Enter an exact number as an integer, fraction, or decimal.)

Answer 1

The statistical software output for this problem is:

From above output:

a) df(Num) = 2

b) df(Denom) = 21

c) Test statistic = 8.92

d) p - Value = 0.0016

e) alpha = 0.05