EXAMPLE 16.1 Perform the Significance Test

CASE 16.1 In Case 16.1, , , and there are observations in all. The sum of ranks for the 12 Used Auto consumers has mean

and standard deviation

The observed sum of the ranks, , is higher than the mean by a bit more than two standard deviations since . It appears that the data support the suspicion that Used Auto consumers are being discriminated against regarding price. The -value for our one-sided alternative is , the probability that is at least as large as the value for our data when is true.