Question

You are using data from a simple random sample to test the given hypotheses. Which of the following collections of observations is further required to justify the use of a t distribution to compute the P-value?
-The distribution of the cholesterol levels of the residents of the state is close to normal
-The distribution of the cholesterol levels of the residents of the state is close to normal, with an unknown mean.
-The distribution of the cholesterol levels of the residents of the state is close to normal, with an unknown mean and an unknown SD.