Applying For A Job

There are three people applying for the same job. One is a mathematician, one a statistician, and one an accountant. The interviewing committee first calls in the mathematician.
They say "we have only one question. What is 500 plus 500?"
The mathematician, without hesitation, says "1000."
The committee sends him out and calls in the statistician. When the statistician comes in, they ask the same question.
The statistician ponders the question for a moment, and then answers "1000... I'm 95% confident."
He is then also thanked for his time and sent on his way. When the accountant enters the room, he is asked the same question: "what is 500 plus 500?"
The accountant replies, "what would you like it to be?"
They hire the accountant.