Question: Public Health and Nutrition Beef boullion generally has a high salt content, which can cause health problems. A food columnist for a local newspaper suggested simmering boullion with slices of raw potato to remove salt. To check this claim, 10 different boullion brands were selected at random and the salt content in each was measured (in mg/cup of water). Five potato slices were then added to each broth and the mixtures were left to simmer for 15 minutes. Following this procedure, the salt content was measured again. The difference between the initial and the final salt content was computed for each boullion brand, and the data are given in the following table.

Assume normality. Is there evidence to suggest that simmering with raw potatoes decreases the mean salt content in beef boullion? Use a = 0.05.