1. 3/4 + 4 5/6 =
2. 15 5/9 + 2 3/4 + 18 7/9 + 6 1/4 A.41 1/3 B.42 7/9 C.43 1/3 D.45
3. 1 3/8 + 3 5/9 + 1 1/8 =
4. 2 5/8 − 1 1/3 =
5. 5 1/3 − 2 2/7

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.