17. (10 points) A pharmaceutical company is testing a new blood pressure medication, which it claims lowers systolic blood pressure in patients with hypertension. Results for randomly selected patients are shown in the table, where the values are systolic blood pressures (in mm Hg) before and one month after the medication is administered. Are the patients' systolic blood pressures, on average, lower after receiving the medication? Test at the 1% significance level. Assume the differences are normally distributed with no outliers. 18. (10 points) The following data represent the cost (in dollars) of a gallon of regular unleaded gasoline at various times during the years of 2020, 2021, and 2022. At the a = 0.05 significance level, test the claim that at least one of the mean annual costs per gallon is different from the others. WEE mm- \"IE "m IE\" -EEIIEE IE.\" Source of Variation Factor (Between) Error (Within) -