# How to perform a Z-Test Step by Step on the TI 89 using Statistics Made Easy

Here is a sample problem: A student who works in the blood lab plans to test the hypothesis that the mean cholesterol level of men is less than 230 mg/dL. The population variance of cholesterol level is assumed to be (40 mg/dL)^2. The student tested nine men for cholesterol levels and found the following values… (read more)