Marlo Stanfield's operation also uses large quantities of prepaid cell phones, on average 1500 per week with a standard deviation of 145. The lead time for their own brand of prepaid cell phones is three weeks and they have a lot size of 350 phones. To ensure they never run out, they keep a safety stock of 500 phones with Proposition Joe.

1) What is the standard deviation of demand during lead time?

A) 251 phones

B) 2187 phones

C) 4500 phones

D) 4751 phones

2) What is the expected shortage per cycle under this policy?

A) 1 phone

B) 2.2 phone

C) 4.5 phone

D) 9.8 phone

3) What is the fill rate under this policy?

A) 0.9398

B) 0.9833

C) 0.9921

D) 0.9938

4) What safety stock should be held to put the expected shortage per cycle at 5 phones?

A) 418 phones

B) 433 phones

C) 462 phones

D) 487 phones

5) What safety stock should be held to put the fill rate at 0.99?

A) 251 phones

B) 145 phones

C) 454 phones

D) 100 phones