A jar is filled with 1,500 marbles and customers of a bank can enter a contest to guess the correct percentage of blue marbles. How can an employee at the bank estimate the actual percentage without physically counting all 1,500 marbles? Learners answer a series of questions designed to help them understand how data from a random sample can be used to make estimations of actual percentages. One suggested modification would be to use a smaller number of marbles in order to conduct actual random samples with your class.