solve using 4 steps in hypothesis testing. The manufacturer of a particular brand of peanut butter claims that the mean fat content per serving of peanut butter is 15 grams wit a standard deviation of 1.8 grams. Hoseok, a dietician, wants to verify this statement so he collects a sample of 81 servings and noted their fat contents. He determined that the mean fat content of the sample is 15.6 grams. is the fat content per serving of a peanut butter significantly different from what the manufacturer stated? Use a=0.001