Here are the saturated fat content (in grams) for several pizzas sold by two national chains.

Dominos 17, 12, 10, 8, 8, 10, 10, 5, 16, 16, 8, 12, 15, 7, 11, 11, 13, 13, 11, 12

Papa John's 6, 7, 11, 9, 4, 4, 7, 9, 11, 3, 4, 5, 8, 5, 5

a. We want to know if Dominos has significantly higher mean saturated fat content than Papa John's pizza. How do you create a 90% confidence interval for the difference in fat content in pizza sold by the two chains and perform a significance test and what would it be.

b. Compare your interval, p-value and t-scores. Is there evidence that Dominos has significantly higher mean saturated fat content than Papa John's pizza?