A major car manufacturer was interested in whether its midsize car was selling consistently in two markets with respect to the annual income of the car purchasers.Five-hundred new car buyers in Chicago and Miami were surveyed.In Chicago,the following pattern was observed:

Question

A major car manufacturer was interested in whether its midsize car was selling consistently in two markets with respect to the annual income of the car purchasers.Five-hundred new car buyers in Chicago and Miami were surveyed.In Chicago,the following pattern was observed: < $20,000 5%;$20,000-$29,999 0%;$30,000-$39,999 40%;$40,000-$49,999 30%;≥ $50,000 5%.Among those surveyed in Miami,20 earned under $20,000;70 earned between $20,000 and $30,000;265 earned between $30,000 and $40,000;125 earned between $40,000 and $50,000;and 20 earned more than $50,000.The chi-square test was used to check whether Miami sales among income groups were consistent with Chicago's.The appropriate degrees of freedom for the chi-square test would be
A)4
B)5
C)500
D)499
E)None of these are correct.

Quizplus · Accepted Answer

The degrees of freedom for a chi-square test comparing two distributions with k categories is (k-1). Since there are 5 income categories, the degrees of freedom would be 5-1 = 4.

A Major Car Manufacturer Was Interested in Whether Its Midsize