Understanding expected value using standard deviation

[kay43]

Question: The manager of a popular seafood restaurant estimates that the daily consumption of shrimp is normally distributed with a mean of 15 pounds and a standard deviation of 2.7 pounds. He makes it a point to buy the right amount of shrimp every day to prevent waste and shortage. Calculate the amount of shrimp that should be bought daily so that it meets demand 92% of the days.

I'm under the impression to use the mean/expected value equation: ExP(x), but I'm not sure which values to place into the formula (my textbook doesn't use standard deviation in any of the examples). Or is this question binomial distribution probability? Can anyone help me better understand how to compute this?

 

[Dr.Peterson]

When you say "ExP(x)", do you mean "[MATH]\sum xP(x)[/MATH]"? That is used when you are given a discrete distribution, that is, a list of all possible values and their probabilities. You don't have that here.

The key words here are "normally distributed". Have you learned how to work with a normal distribution (finding z-scores, looking up probabilities, etc.)?