mg . We choose dL We want to conduct a hypothesis test of the claim that for middle-aged adults the population mean of their cholesterol levels is less than 191.8 mg and a standard deviation of 18.5...

Extracted text: mg . We choose dL We want to conduct a hypothesis test of the claim that for middle-aged adults the population mean of their cholesterol levels is less than 191.8 mg and a standard deviation of 18.5 dL mg a random sample of such levels. The sample has a mean of 195.8 TP For each of the following sampling scenarios, choose an appropriate test statistic for our hypothesis test on the population mean. Then calculate that statistic. Round your answers to two decimal places. (a) The sample has size 12, and it is from a normally distributed population with an unknown standard deviation. Aa It is unclear which test statistic to use. (b) The sample has size 13, and it is from a population with a distribution about which we know very little. %3D OIt is unclear which test statistic to use.