A researcher collected sample data for 20 middle-aged women. The sample had a mean serum cholesterol level (measured in milligrams per one hundred milliliters) of 191.4, with a standard deviation of 7.8. Assuming that serum cholesterol levels for middle-aged women are normally distributed, find a 90% confidence interval for the mean serum cholesterol level of all women in this age group. Give the lower limit and upper limit of the 90% confidence interva Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. (If necessary, consult a list of formulas.) Lower limit: X 5 ? Upper limit