A large department store examined a sample of the 18 credit card sales and recorded the amounts charged for each of three types of credit cards: MasterCard, Visa and American Express. Six MasterCard sales, seven Visa and five American Express sales were recorded. The store used ANOVA to test if the mean sales for each credit card were equal. What are the degrees of freedom for the F statistic?
A) 18 in the numerator, 3 in the denominator.
B) 3 in the numerator, 18 in the denominator.
C) 2 in the numerator, 15 in the denominator.
D) 0 in the numerator, 15 in the denominator.

Question

Quizplus · Accepted Answer

The degrees of freedom for the F statistic in ANOVA are calculated as follows: For the numerator (between groups), it's the number of groups minus one, which is 3 - 1 = 2. For the denominator (within groups), it's the total number of observations minus the number of groups, which is 18 - 3 = 15.

A Large Department Store Examined a Sample of the 18