a public health investigator wishes to determine whether a new anti-smoking film actually reduces the daily consumption of cigarette by heavy smokers. The mean daily cigarette consumption is calculated consumption for each of eight heavy smokers during the month before the film presentation and also during the month after the film presentation, with the following results: mean daily cigarette

to find the dependent 2 sample mean daily cigarette consumption the smoker number is 1,2,3,4,5,6,7,and 8. Before Film (X1) 28,29,31,44,35,20,50,25 After Film (X2)26,27,32,44,35,16,47,23 Difference (X1-X2) D2this is part of the question I am looking for the answer