Confidence interval for the population mean: Use of the t distribution

A researcher collected sample data for 18 women ages 18 to 24 . The sample had a mean serum cholesterol level (measured in mg/100 mL) of 1909.9 , with a standard deviation of 7.7 . Assuming that serum cholesterol levels for women ages 18 to 24 are normally distributed, find a 90% confidence interval for the mean serum cholesterol level of all women in this age group. Then complete the table below.

Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place.


What is the lower limit of confidence level?
What is the upper limit of confidence level?

Hi, pthomas21!

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Thanks!