Exercise 104 Page 620

If there is an association between the amount of cheese and where a taco was purchased, the percentages of Taco Shack shops who give less cheese should be greater or lesser when compared to the competitors. Therefore, we should calculate the relative frequency of the number of shops in each of the intervals.

< 15 grams cheese between 15 and 25 g cheese > 25 grams cheese total \frac{1 5}{1 3 8} \frac{8 3}{1 3 8} \frac{4 1}{1 3 8} 138 \frac{1 1}{1 1 2} \frac{6 8}{1 1 2} \frac{3 3}{1 1 2} 112

Let's calculate the different relative frequencies.

< 15 grams cheese between 15 and 25 g cheese > 25 grams cheese total 11 % 60 % 30 % 138 10 % 61 % 29 % 112

As we can see, the relative frequencies are roughly the same, which means there is no association and no merit to the online complaints.