I have come across this question and cannot seem to do the calculation in the BA II calculator. The question is:
Use the probability distribution to calculate the standard deviation for the portfolio
State of economy Prob Return
Boom 0.30 15%
Learning objectives: Estimate the mean, variance, and standard deviation using sample data. Explain the difference between a population moment and a sample moment. Distinguish between an estimator and an estimate. Describe the bias of an estimator and explain what the bias measures.
The simple, common approach to estimating volatility is historical standard deviation. Here is a thread about the decision to include/exclude the mean return: https://trtl.bz/2kLRK7z
David's XLS is here: https://trtl.bz/2kOmHb6
Learning objectives: Interpret and apply the mean, standard deviation, and variance of a random variable. Calculate the mean, standard deviation, and variance of a discrete random variable. Interpret and calculate the expected value of a discrete random variable.