A marketing research analyst selects a random sample of ten customers out of the fourty

who purchased a particular item from central store. The sample one of ten customers purchased

different item from central store i.e. 11, 37, 25, 62, 51, 21, 18, 16,17, 18, 19 11, 32, 20 and the

sample of other ten customers purchased different items from central store i.e 5,11,4,7,8,12, 13,

14, 15 16,18,17,16,11. If a random sample of ten items are selected of both customers, what is

the probability that customer will have a mean item which is a) at least thirty one b) at most fourty

five c) between thirty nine and fifty six d) mean item is fifty percent and e) mean item is hundred

percent.