Assume that a sample is used to estimate a population mean

Find the 99.5% confidence interval for a sample of size 38 with a mean of 56.1 and a standard deviation of 21.1. Enter your answer as anopen-interval(i.e., parentheses) accurate to one decimal place (because the sample statistics are reported accurate to one decimal place).

99.5% C.I. =

Answer should be obtained without any preliminary rounding. However, the critical value may be rounded to 3 decimal places.