3) The manager of a grocery store wants to estimate the percentage of his customers
who like orange juice. He surveys the first 10 customers on a Monday morning.
Which statements are true? Select each correct statement by circling the letter(s).
a) The manager’s sample is unlikely to be biased because the first 10 customers on
Monday morning represent all his customers.
b) The manager can improve his estimate by surveying 50 customers instead of 10.
c) The manager can improve his estimate by randomly selecting customers
throughout the week.
d) The only way the manager can estimate the percentage is to ask every customer
throughout the week.