15.17 Attitudes toward secondhand stores. To study customers’ attitudes toward secondhand stores, researchers interviewed samples of shoppers at two secondhand stores of the same chain in two cities. Here are data on the incomes of shoppers at the two stores, presented as a two-way table of counts:10 Income City 1 City 2 Under $10,000 70 62

$10,000 to $19,999 52 63

$20,000 to $24,999 69 50

$25,000 to $34,999 22 19

$35,000 or more 28 24

(a) Is there a relationship between city and income? Use the chi-square test to answer this question.

(b) The chi-square test ignores the ordering of the income categories. The data file ex15 11 contains data on the 459 shoppers in this study. The first variable is the city (City1 or City2) and the second is the income as it is coded in the table above. Is there good evidence that shoppers in one city have systematically higher incomes than in the other?