The owner of Britten's Egg Farm wants to estimate the mean number of eggs laid per chicken. A sample of 20 chickens shows they laid an average of 19 eggs per month with a standard deviation of 2.84 eggs per month. (a-1) What is the value of the population mean? (a-2) What is the best estimate of this value? (c) For a 95 percent confidence interval, the value of t is . (Round your answer to 3 decimal places.) (d) The 95 percent confidence interval for the population mean is to (Round your answers to 3 decimal places.)