Although many people think they can put a meal on the table in a short period of time, an article reported that they end of spending about 40 minutes doing so. Suppose another study is conducted to test the validity of this statement. A sample of 25 people is selected, and the length of time to prepare and cook dinner (in minutes) is recorded with the following results in (Dinner): sample of 50 cans, and the mean amount of paint per 1-gallon can is 0.995 gallon.

44.0   51.9   49.7   40.0   55.5   33.0    43.4   41.3  45.2   40.7   41.1   49.1   30.9

45.2   55.3   52.1   55.1   38.8    43.1   39.2   58.6   49.8   43.2   47.9   46.6

a. Is there evidence that the population time to prepare and cook dinner is different from 40 minutes?  Use the p-value approach and a level of significance of 0.05.

b. What assumption about the population distribution is needed in order to conduct the t test in (a)?

c. Make a list of the various ways you could evaluate the assumption noted in (b).

d. Evaluate the assumption in (b) and determine whether the t test in (a) is valid.