Tubby's Tubes wants to improve their productivity. Their process yield is currently 90.90% based on 9480 pounds of PVC plastic. If they are going to improve their productivity to 93.50, how many tubes will they have to produce from the same amount of plastic input?

When a company produces and sells x thousand units per week, its total weekly profit is p thousand dollars, where upper p equals startfraction 800 x over 100 plus x squared endfraction . the production level at t weeks from the present is x equals 4 plus 2 t. find the marginal profit, startfraction dp over dx endfraction and the time rate of change of profit, startfraction dp over dt endfraction . how fast (with respect of time) are profits changing when tequals8?