**ECONOMICS**

1. The cost C in dollars of producing x items is given by the rule:

C(x) = 2600 + 2x +.001x

a. What is the marginal cost if 100 items are produced?

b. At what number of items is the average cost a minimum?

2. A factory manufactures cylindrical cans which cost 2 cents for the sides and 8 cents for the top and bottom of the cans. If the volume of the can is to be 1000 cubic centimeters, what should be the radius of the can to minimize the cost of manufacture?

3. A box containing 1200 cubic centimeters with a square base and an open top is to be constructed. What should be the dimensions in order to minimize the amount of material?