If strep bacteria causes the infection, it can remain contagious for up to 2 weeks without treatment. However, antibiotics can shorten the contagious period and li â¦ mits to about 24 to 48 hours once the therapy starts.     http://health.top54u.com/post/How-Long-is-Tonsillitis-Contagious.aspx.
Calculate Options Implied Volatility in Excel. Implied Volatility Function: Returns the annualized volatility of an underlying security implied by the market price of a European call or put option on that security, based on Black-Scholes valuation. Description of parameters.
= ((FV/PV)^(1/n)) â 1. Where FV is the investmentâs ending value, PV is its ending value, and n is the # of years. The XIRR function in Excel also calculates an internal rate of return (IRR) that can also be used to calculate the CAGR. The XIRR function is: