Math
posted by Jackie .
Experience shows that a ski lodge will be full ( 156 guests) if there is a heavy snow fall in December, while only partially full ( 57 guests) with a light snow fall. What is the expected number of guests if the probability for a heavy snow fall is .40?
If someone could please explain to me how to do this, I would greatly appreciate it. I have several problems that are just like this, and if someone can teach me how to do this, then I will know how to do the other ones.

Expected value = 156 x (probability of snow) + 57 x (probability of no snow)
Although there either will or will not be show, and the number of guests will closer to either 156 or 57, the "expected value" is the average over many similar situations.
When gambling, as in business, it is usually best to assume the expected value will occur.