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 $66\%$ probability that the

firm will have a $26\%$ return and a $34\%$ probability that the firm will have a $-5\%$ return. What is the volatility $($standard deviation$)$ of a portfolio that consists of an equal

investment in:

a$.18$ firms of type $S?$

b$.18$ firms of type I?

a$.$ What is the volatility $($standard deviation$)$ of a portfolio that consists of an equal investment in $18$ firms of type S$?$

Standard deviation is $,$ o$.($Round to two decimal places.$)$

b$.$ What is the volatility $($standard deviation$)$ of a portfolio that consists of an equal investment in $18$ firms of type I?

Standard deviation is $-\%.($Round to two decimal places.$)$