Question: The Internet Revenue Services uses a letter-opening machine to remove checks from envelopes. This machine has probability p=0.03 of failure for any envelope. On a certain day, n=500, envelopes are independently handled by the machine. Let Y be the number of envelopes for which the machine fails to remove a check. Use the Central Limit Theorem the Central Limit Theorem to approximate \[P\{Y\le 10\}\].