Please explain

Baby weight: Following are weights, in pounds, of 11 two-month-old baby girls. It is reasonable to assume that the population is approximately normal. 11.87 12.32 11.48 9.34 12.23 8.63 14.13 12.95 10.30 12.34 11.48 Send data to Excel Part: 0 / 2 Part 1 of 2 Construct a 99.5% interval for the mean weight of two-month-old baby girls. Round the answers to three decimal places. A 99.5% confidence interval for the mean weight of two-month-old baby girls is 10.085 13.155