You would like to construct a 99% confidence interval to estimate today's population mean temperature, so you make a series of measurements (a random sample) throughout the day. The mean of these measurements is 64 degrees Fahrenheit, and their standard deviation is 3 degrees Fahrenheit. (a) What is the best point estimate, based on the sample, to use for the population mean? X 64 degrees (b) For each of the following sampling scenarios, determine which distribution should be used to calculate the critical value for the 99% 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 Unclear either Z ort X The sample has size 17, and it is from a normally distributed O O O O population with an unknown standard deviation. The sample has size 13, and it is from a population with a O O O O distribution about which we know very little. The sample has size 75, and it is from a non-normally distributed e O population with a known standard deviation of 4