Information for Questions 20 - 22: The $ & P 600 is a collection of 600 stocks of publicly traded companies. Using data obtained from Yahoo!Finance, the monthly rates of return of the $ & P 600 from 1950 through 2010 are normally distributed. The mean rate of return is 0.007443 and the standard deviation is 0.04135. 20. What lo the probability that a randomly selected month has a pooltive rate of return? That Is, what Is PDX(> 0)? * O 0.36 O 0.57 0.43 21. What Is the probability that the mean monthly return for a one year period Is positive? That le, for n = 12 months, what Is P(X > 0) ?* O 0.73 0.43 O 0.57 O 0.27 O 0.50 12. What Is the probability that the mean monthly return for a five year period Is positive? That Is, for n = 60 months, what Is PO( 0)? * O 0.02 O 0.50 O 0.08 O 0.84