"What do two plus two equal?

A mathematician , an accountant and an economist apply for the same
job. The interviewer calls in the mathematician and asks "What do two
plus two equal?"
The mathematician replies "Four." The interviewer asks "Four,
exactly?" The mathematician looks at the interviewer incredulously and
says "Yes, four, exactly."

Then the interviewer calls in the accountant and asks the same
question "What do two plus two equal?" The accountant says "On
average, four - give or take ten percent, but on average, four."

Then the interviewer calls in the economist and poses the same
question "What do two plus two equal?"

The economist gets up, locks the door, closes the shade, sits down
close to the interviewer and says "What would you like it to equal?"