Item 8 a store hands out 900 reward cards. customers scan their cards in the store to find out what reward they receive. the probability that a customer receives a $25 gift card is 1/12. how many customers receive a $25 gift card?

Monitors manufactured by tsi electronics have life spans that have a normal distribution with a standard deviation of 1800 hours and a mean life span of 20,000 hours. if a monitor is selected at random, find the probability that the life span of the monitor will be more than 17,659 hours. round your answer to four decimal places.