problem: Consider an economy with two types of firms, S and I.S firms all move together. I firms move independently. For both types of firms, there is a 60 percent probability that the firms will have a 15% return and a 40 percent probability that the firms will have a – ten percent return. Determine the volatility [standard deviation] of a portfolio that consists of an equal investment in 20?
[A] Type S firms?
[B] Type I firms?