Expected Value

I need to find the small medium and large EV for the following information. how in the HECK do I do that?

Worst Base Best
Probability .10 .60 .30
Small 400 500 660
Medium -250 650 800
Large -400 580 990

5year planning would be a factor

I also need to know how to compute this if the worst case scenerio increase to.2 base case decreases to .5 & best case stays at .3

finally if a suggested expenditure of %150000 over the planning would this reduce the worst case?? They are exzpeted to increase the best case to .4 would this be a good investment?

HELP I"m LOST

Probability .10 .60 .30
Small 400 500 660

0.10*400 + 0.60*500 + 0.30*660 = ???

You do the other two.