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% probability that the firm will have a 15% return and a 40% probability that the firm will have a 10% return. What is the volatility (standard deviation) of a portfolio that consists of an equal investment in: a. 20 firms of type S? b. 20 firms of type I? a. What is the volatility (standard deviation) of a portfolio that consists of an equal investment in 20 firms of type S? Standard deviation is \%. (Round to two decimal places.)