What piece of equipment on a boat is most important in preventing propeller strike injuries?

It is week 1 and there are currently 20 as in stock. we need 300 as at the start of week 5. if there are scheduled receipts planned for week 3 and week 4 of 120 as each and a has a lead time of 1 week, when and how large of an order should be placed to meet the requirement of 300 as?

Suppose an economy consists of three sectors: energy (e), manufacturing (m), and agriculture (a). sector e sells 70% of its output to m and 30% to a. sector m sells 30% of its output to e, 50% to a, and retains the rest. sector a sells 15% of its output to e, 30% to m, and retains the rest.

The lee family is looking to buy a house in one of two suburban areas just outside of a major city, and air quality is a top priority for them. overall air quality is calculated by taking measures in 100 locations within each suburb and then calculating a measure of central tendency. in one suburb, there is a major bus station that creates very poor air quality at its location but has no impact in the surrounding parts of the suburb. in this situation, which measure of overall suburb air quality would be most useful?