"Miles" wrote:
A car wash makes $4000 profit on sunny days and loses $4000 on
non-sunny days. Assuming independence, if it is sunny 75% of the
days, (and, therefore NOT sunny 25% of the days) what is the expected
(daily) profit (or loss) for the car wash? (MEAN = EXPECTED VALUE)

This has nothing to do with Excel. You should post to a sci.stat.*
newsgroup. But FYI, they normally do not answer homework
assignment questions.

PS: The answer is 0.75*4000 - 0.25*4000 = 4000*0.50.