The manager of store A is aware that waiting times are much longer if the customer makes an order with a special request. From past experience this occurs 20% of the time. If we monitor the next 10 customers,
(a) What is the probability that half or more of these customers make a special request?
(b) What assumptions do you need to make to find this probability?
Out of the next 100 customers,
(c) There is a probability of 90% that the number of customers make a special request equals or exceeds what value?