Assume that a sample is used to estimate a population mean $\mu$. Find the 95% confidence interval for a sample of size 57 with a mean of 22.5 and a standard deviation of 10.4. Enter your answer as an open-interval (i.e., parentheses) accurate to one decimal place (because the sample statistics are reported accurate to one decimal place).
95% C.I. =
Answer should be obtained without any preliminary rounding. However, the critical value may be rounded to 3 decimal places.