What is the value of x?

In the diagram of circle a what is m

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.

Rachel is baking a cake but does not know if she wants to make a round or a square cake which cake has a larger area a round 8 inch cake or a square 9 inch cake