Test of Two Variances · Exercise 18

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 as follows.

$$\begin{array}{ccc}\text{working-class}& \text{professional (middle incomes)}& \text{professional (wealthy)}\\ \text{17.8}& \text{16.5}& \text{8.5}\\ \text{26.7}& \text{17.4}& \text{6.3}\\ \text{49.4}& \text{22.0}& \text{4.6}\\ \text{9.4}& \text{7.4}& \text{12.6}\\ \text{65.4}& \text{9.4}& \text{11.0}\\ \text{47.1}& \text{2.1}& \text{28.6}\\ \text{19.5}& \text{6.4}& \text{15.4}\\ \text{51.2}& \text{13.9}& \text{9.3}\end{array}$$
Determine whether or not the variance in mileage driven is statistically the same among the working class and professional (middle income) groups. Use a 5% significance level.
Use the following information to answer the next two exercises. lists the number of pages in four different types of magazines.

$$\begin{array}{cccc}\text{home decorating}& \text{news}& \text{health}& \text{computer}\\ \text{172}& \text{87}& \text{82}& \text{104}\\ \text{286}& \text{94}& \text{153}& \text{136}\\ \text{163}& \text{123}& \text{87}& \text{98}\\ \text{205}& \text{106}& \text{103}& \text{207}\\ \text{197}& \text{101}& \text{96}& \text{146}\end{array}$$

Its source prints no answer for this problem, so there's nothing to check against.

OpenStax, Introductory Statistics 2e · §13.4 Test of Two Variances · Exercise 18