please check if my answers are correct but only answer if you for sure know the answers. I've been getting a lot of wrong responses.

Anvils Works' requires, on average, 2,900 tons of aluminum each week, with a standard deviation of 1,100 tons. The lead time to receive its orders is 12 weeks. The holding cost for one ton of aluminum for one week is $9. It operates with a 0.99 in-stock probability. Use Table 11.5. (Round your answer to nearest integer.) a. On average, how many tons does it have on order? tons (Round your answer to nearest integer.) b. On average, how many tons does it have on hand? tons (Round your answer to nearest integer.) c. If its average inventory was 4,500 tons, what would be its average holding cost per week? per week (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? per ton (Round your answer to 4 decimal places.) e. Suppose its on-hand inventory is 4,875 tons, on average. What in-stock probability does it offer to its customers? TABLE 11.5 In-Stock Probabilities and Matching Safety Factors, z