Jerry: Thanks. The formula works perfectly. The purpose of this formula
is to determine the volatilty on a series of monthly stock / index returns.
Many in the investing community have found this approach to be optimal for
determining the historical volatility of a particular trading strategy.

Ron: Yes, you are right. The method I'm employing is exactly based on the
presentation by Sharpe himself. I am annualizing the results using the
SQRT(12) at the end of the formula.