Q.3 Using a people-counting device at the entry to a particular department store in Sydney, the average number of shoppers visiting the store during any one-hour period was determined as 448 shoppers with a standard deviation of 21 shoppers.
(a) What is the probability that a random sample of 49 different one-hour shopping periods will yield a sample mean between 441 and 446 shoppers?
(b) Interpret your answer in words.
(c) If the random sample size increased to 196 what effect will this have on the standard error of the mean?