The average stock price for companies making up the S&P 500 is $30, and the standard deviation is $8.20 (BusinessWeek, Special Annual Issue, Spring 2003). Assume the stock prices are normally distributed. a. What is the probability a company will have a stock price of at least $40?
b. What is the probability a company will have a stock price no higher than $20?
c. How high does a stock price have to be to put a company in the top 10%?