Researchers are testing the effectiveness of a new smoking cessation program. At the close of the program the mean number of cigarettes smoked for the 328 people who completed the program was 4.3 with a standard deviation of 5.22. The mean number of cigarettes smoked per day for the 298 people who did not complete the program was 13 with a standard deviation of 8.97. Construct a two-sided 95% confidence interval for the difference between means.