Between 2000 and 2015, the average daily return of S&P 500 was 0.000022 (yes, it is so low, just 0.0022%. But remember it is daily returns), with standard deviation .01227. Assume that the returns follow a normal distribution (actually, stock returns have a distribution that has longer tails than those of a normal distribution).
a) What is the coefficient of variation? Comment on this value.
b) What is the probability of a day 's return being greater than 0.000022?
c) What is the probability of a day 's return being less than 0?