Weekly demand at a grocery store for a brand of cereal is normally distributed according to X ~ N(800 boxes, 752 boxes).

a. What is the probability that the demand next week is less than 959 boxes?
b. What is the probability that the demand next week is more than 1004 boxes?
c. How many boxes should the store order for next week to have only a 2.5 percent chance of running short of the cereal?

If you still need this try Excel:

a) =normdist(959,800,752,true) (.5837)
b) =1-normdist(1004,800,752,true) (.3931)
c) Use solver and set target cell to value of .975 (2274)