Remember, the expected value of a probability distribution is a statistical measure of the average (mean) value expected to occur during all possible circumstances. To compute an assets expected return under a range of possible circumstances (or states of nature), multiply the anticipated return expected to result during each state of nature by its probability of occurrence.

Consider the following case:

David owns a two-stock portfolio that invests in Blue Llama Mining Company (BLM) and Hungry Whale Electronics (HWE). Three-quarters of Davids portfolio value consists of BLMs shares, and the balance consists of HWEs shares.

Each stocks expected return for the next year will depend on forecasted market conditions. The expected returns from the stocks in different market conditions are detailed in the following table:

Market Condition	Probability of Occurrence	Blue Llama Mining	Hungry Whale Electronics
Strong	0.20	47.5%	66.5%
Normal	0.35	28.5%	38%
Weak	0.45	-38%	-47.5%

Calculate expected returns for the individual stocks in Davids portfolio as well as the expected rate of return of the entire portfolio over the three possible market conditions next year.

	The expected rate of return on Blue Llama Minings stock over the next year is .
	The expected rate of return on Hungry Whale Electronicss stock over the next year is .
	The expected rate of return on Davids portfolio over the next year is .

The expected returns for Davids portfolio were calculated based on three possible conditions in the market. Such conditions will vary from time to time, and for each condition there will be a specific outcome. These probabilities and outcomes can be represented in the form of a continuous probability distribution graph.

For example, the continuous probability distributions of rates of return on stocks for two different companies are shown on the following graph:

Based on the graphs information, which companys returns exhibit the greater risk?

Company H

Company G

PROBABILITY DENSITY Company G Company H -40 -20 40 60 0 20 RATE OF RETURN (Percent)