Kelli calls her grandmother every month. every other month, kelli also calls her cousin. if kelli calls her cousin in january, how many calls kelli have made to her grandmother and her cousin by the end of august.?

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.