HELP: Static simulation?

Artie Siegel, an MBA student, has been having problems balancing his checkbook. His monthly income is derived from a graduate research assistantship; however, he also makes extra money in most months by tutoring undergraduates in their quantitative analysis course. His historical chances of various income levels are shown in the following table: *Assume that this income is received at the beginning of each month. Siegel's expenditures also vary from month to month, and he estimates that they will follow a normal distribution with a mean of $450 and a standard deviation of $50. He begins his final year with $600 in his checking account