Determine which of the following subsets of r 3 are subspaces. briefly explain. i) the set s1 of vectors (x, y, z) ∈ r 3 such that xyz = 0 ii) the set s2 of vectors (x, y, z) ∈ r 3 such that x + y + z = 0 iii) the set s1 of vectors (x, y, z) ∈ r 3 such that y 2 + z 2 = 0 iv) the set s1 of vectors (x, y, z) ∈ r 3 such that y 2 − z 2 = 0

Southeastern bell stocks a certain switch connector at its central warehouse for supplying field service offices. the yearly demand for these connectors is 15,000 units. southeastern estimates its annual holding cost for this item to be $25 per unit. the cost to place and process an order from the supplier is $75. the company operates 300 days per year, and the lead time to receive an order from the supplier is 2 working days. a) find the economic order quantity. b) find the annual holding costs. c) find the annual ordering costs. d) what is the reorder point?

What would happen to the equilibrium price and quantity of lattés if the cost to produce steamed milk

Thomas kratzer is the purchasing manager for the headquarters of a large insurance company chain with a central inventory operation. thomas's fastest-moving inventory item has a demand of 6,000 units per year. the cost of each unit is $100, and the inventory carrying cost is $10 per unit per year. the average ordering cost is $30 per order. it takes about 5 days for an order to arrive, and the demand for 1 week is 120 units. (this is a corporate operation, and the are 250 working days per year.)a) what is the eoq? b) what is the average inventory if the eoq is used? c) what is the optimal number of orders per year? d) what is the optimal number of days in between any two orders? e) what is the annual cost of ordering and holding inventory? f) what is the total annual inventory cost, including cost of the 6,000 units?