Which step is not necessary when solving this system of equations by graphing? Identify the point of intersection. Choose a method to graph the equations. Determine the shaded area for each line. Write the solution as an ordered pair.

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.