Forty-two straws have been collected: Six of them are 8 inches long, twelve are 4 inches long. and twenty-four are 2 inches long. The average length of this set of straws is 3.43 inches. All forty-two straws are placed into a bag and twenty are withdrawn from the bag and measured. Each straw is returned to the bag after being recorded so that there are always forty-two straws to select from. The average length of the twenty straws is 4.63 inches.