Consumers were surveyed on the relative number of visits to a Sears store (often, occasionally, and never) and if the store was in an enclosed mall (yes and no). When variables such as these data are measured nominally, the results are usually summarized in a contingency table.
Enclosed Mall
Visits Yes No Total
Often 60 20 80
Occasional 25 35 60
Never 05 50 55
Total 90 105 195
(a) Are the number of visits and enclosed mall variables independent? Why? Interpret your conclusion. (b) Draw a tree diagram and determine the joint probabilities