Screen printing a batch of shirts requires 2 minutes per shirt in addition to 1 minute of initial set up time. How long does it take to screen print a batch of 4 shirts. Write and solve an equation to find the answer.

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.