Blood glucose levelsfor obese patients have a mean of 98 mg/dl with a standard deviation of 14.2 mg/dl. A researcher thinks that a diet high in raw cornstarch will have a positive effect on blood glucose levels. A sample of 28 patients who have tried the raw cornstarch diet have a mean glucose level of 103.4 mg/dl.

Conduct the test that the raw cornstarch die had an effect at the 0.05 significance level.  Be sure to show all steps.