You would like to construct a 95% confidence interval to estimate the population mean price of milk (per gallon) in your city. You select a random sample of prices from different stores. The sample has a mean of 3.65 dollars and a standard deviation of 0.29 dollars. (a) What is the best point estimate, based on the sample, to use for the population mean? |dollars (b) For each of the following sampling scenarios, determine which distribution should be used to calculate the critical value for the 95% confidence interval for the population mean. (In the table, Z refers to a standard normal distribution, and t refers to a t distribution.) Could use Sampling scenario Z t Unclear either Z or t The sample has size 20, and it is from a normally distributed population with an unknown standard deviation. The sample has size 100, and it is from a non-normally distributed population. The sample has size 80, and it is from a non-normally distributed population with a known standard deviation of 0.28.