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!

We do help people with homework on this site. But, the keyword here is "help". We don't directly answer homework questions for students here. If we did, how would that be helping them to learn how to come up with the answers themselves?

If you use this site to get help with your homework, please do take some time to come up with and post what you think might be the answers yourself. If you do that, it's likely that you'll have someone very knowledgeable about whatever subject who'll be willing to discuss with you how and why your answers are correct or incorrect.

Please also read the expectations concerning the posting of homework questions that can be found via clicking on the following link.

Ask Me Help Desk - Announcements in Forum : Homework Help (https://www.askmehelpdesk.com/math-sciences/announcement-font-color-ff0000-u-b-read-first-expectations-homework-help-board-b-u-font.html)

Thanks!