Wendys fast food resturant sells hamburgers and chicken sand

Wendy\'s fast food resturant sells hamburgers and chicken sandwiches. On a typical weekday, the demand for hamburgers is normally distributed with a mean of 450 and standard deviation of 75; the demand for chicken sandwiches is normally distributed with a mean of 120 and standard deviation of 30. (Assume that the demand for hamburgers and chicken sandwiches are probabilistically independant.)

a. How many hamburgers must the resturant stock to be 99% sure of not running out on a given day?

b. If the resturant stocks 600 hamburgers and 150 chicken sandwiches for a given day, what is the probabitity that it will not run out of hamburgers that day?

c. What is the probability that they dont run out of both hamburgers and chicken sandwhiches? Why is the independance assumption probably not realistic?

Solution