Two components A and B are used as follows: Normal Usage 300 units per week each Maximum Usage 450 units per week each Minimum Usage 150 units per week each Re-order Quantity A-2400 units, B-3,600 units Re-order Period A-4 to 6 weeks; B-2 to 4 weeks Calculate for each component : (a) Re-order Level; (b) Minimum Level; (c) Maximum Level; (d) Average Stock Level