An owner of two cats is trying to decide if it is cheaper to order cat food over the Internet or to buy the food locally. Listed below are the prices (in dollars) quoted for two bags of cat food from various manufacturers. On the average, can we conclude that Internet purchases are significantly less than local store purchases? Test at α = .05
A) Reject the null hypothesis; Internet purchases are less than local stores.
B) Do not reject the null hypothesis; there is not enough evidence to show that Internet purchases are less than local stores.

Question

An owner of two cats is trying to decide if it is cheaper to order cat food over the Internet or to buy the food locally. Listed below are the prices (in dollars) quoted for two bags of cat food from various manufacturers.  On the average, can we conclude that Internet purchases are significantly less than local store purchases? Test at α = .05
A) Reject the null hypothesis; Internet purchases are less than local stores. 
B) Do not reject the null hypothesis; there is not enough evidence to show that Internet purchases are less than local stores.

Quizplus · Accepted Answer

11ead627_0a07_9951_93a1_35a354de4ae6_TB7056_00 T_I = 60 and T_E = 130 Because n_I > n_E, T = T_E = 130 From the Wilcoxon Rank Sum table for n_I= 10 and n_E = 9, T_U = 111. If T ≥ T_U then reject the null hypothesis. Because 130 ≥ 111, we can reject H₀. Thus, we have evidence that Internet purchases are significantly less than local stores.

An Owner of Two Cats Is Trying to Decide If