Demand in each period follows the same normal distribution, with mean mu and standard deviation sigma. Assuming demand is independent across periods, which of the following statements about the standard deviation of demand over five periods is true?

Group of answer choices

a. It equals sigma.

b. It is greater than sigma but less than 5*sigma.

c. It equals 5*sigma.

d. It is even more than 5*sigma

In Jacks store, weekly demand is normally distributed with mean 200 and standard deviation 50. Jack follows an order-up-to policy with zero safety stock. What is the service level in his store?

Group of answer choices

a. 100%

b.75%

c.50%

d. 25%

e Need more information.

I think this one is e^