I have a sample of people (n=36) with a mean cholesterol level of 4.1. The reference table states that the normally distributed population has values between 3.2 and 6.2 (95% confidence interval).
Can I conclude that the sample group has a different cholesterol value than “the normal population”? I have to solve this using a significance level of 0.05, showing all steps required.
I honestly have no idea where to start, but this is how I tried:
xbar = 4.1 n = 36 pop.mean = 4.7 (right?) pop. standard deviation = 0.7653 (not sure about this one either)
I was trying to get the sample standard deviation from the population sd, but I'm not sure if that's possible at all. And that's where I'm stuck. How do I need to approach this?