A candy company fills a 550 g package of Halloween candy with individually wrapped pieces of candy. The number of pieces of candy per package varies because the package is sold by mass. The company wants to estimate the number of pieces per package. Inspectors randomly sample 120 packages of this candy and count the number of pieces in each package. They find that the sample mean number of pieces is 18.72. Assuming a population standard deviation of 0.8735, (6 marks) a) what is the point estimate of the number of pieces per package? b) Construct a 99% confidence interval to estimate the mean number of pieces per package for the population