Using this data, find the 95% confidence interval for the true difference in the number of sit-ups each person can do before and after the course. Assume that the numbers of sit-ups are normally distributed for the population both before and after completing the course. Sit-ups before 57 24 36 46 47 38 38 25 50 36 Sit-ups after 59 32 39 52 58 40 50 27 57 52