All the major stock market indexes posted heavy losses in 2008. The mean one-year return for stocks in the S&P 500, a group of very large companies, was -38.5%. The mean one-year return for the NASDAQ, a group of 3,200 small and medium sized companies, was -40.5^. Historically, the one year returns are approximately normal, the standard deviation in the S&P 500 is approximately 20%, and the deviation in the NASDAQ is approximately 30%.
What is the probability that a stock in the S& P 500 gained value in 2008?
What is the probability that a stock in the S&P 500 gained 10% or more?
What is the probability that a stock in the S&P 500 lost 50% or more in 2008?
What is the probability that a stock in the S&P 500 lost 60% or more?