Your brother, age 40, is the regional manager at an office supply company. He thinks he might want to leave his job to go back to school for an MBA. He expects that his current job if he were to stay at it, would pay him a real income stream of $85,000 per year until retirement at age 65. 
If he goes back to school, he would forego two years of income, but his real income after graduation would be $125,000 per year until retirement at age 65.
He has been accepted to an MBA program that costs a real $25,000 per year.
If his real opportunity cost is 8 percent, would leave his job to get an MBA be a smart financial decision?