What can cause a production possibilities curve to move down and to the left?

Anew 2-lane road is needed in a part of town that is growing. at some point the road will need 4 lanes to handle the anticipated traffic. if the city's optimistic estimate of growth is used, the expansion will be needed in 4 years and has a probability of happening of 40%. for the most likely and pessimistic estimates, the expansion will be needed in 8 and 15 years respectively. the probability of the pessimistic estimate happening is 20%. the expansion will cost $ 4.2 million and the interest rate is 8%. what is the expected pw the expansion will cost?

Your subscription to investing wisely weekly is about to expire. you plan to subscribe to the magazine for the rest of your life, and you can renew it by paying $85 annually, beginning immediately, or you can get a lifetime subscription for $620, also payable immediately. assuming that you can earn 6.0% on your funds and that the annual renewal rate will remain constant, how many years must you live to make the lifetime subscription the better buy?

Problem page a medical equipment industry manufactures x-ray machines. the unit cost c (the cost in dollars to make each x-ray machine) depends on the number of machines made. if x machines are made, then the unit cost is given by the function =cx+−0.3x2126x31,935 . how many machines must be made to minimize the unit cost?