please help I only meed part e the rest are correct.

Anvils Works' requires, on average, 2,600 tons of aluminum each week, with a standard deviation of 900 tons. The lead time to receive its orders is 10 weeks. The holding cost for one ton of aluminum for one week is $10. It operates with a 0.98 in-stock probability. a. On average, how many tons does it have on order? Note: Round your answer to nearest integer. Answer is complete and correct. b. On average, how many tons does it have on hand? Note: Round your answer to nearest integer. Answer is complete and correct. c. If its average inventory was 12,500 tons, what would be its average holding cost per week? Note: Round your answer to nearest integer. Answer is complete and correct. d. If its average inventory was 11,000 tons, what would be its average holding cost per ton of aluminum? Note: Round your answer to 2 decimal places. d. If its average inventory was 11,000 tons, what would be its average holding cost per ton of aluminum? Note: Round your answer to 2 decimal places. Answer is complete and correct. e. Suppose its on-hand inventory is 4,950 tons, on average. What in-stock probability does it offer to its customers? Hint: use the -NORM.S.DIST(2.1) Excel function. Note: Do not round intermediate calculations or your z value. Round your final answer to 4 decimal places. Answer is complete but not entirely correct