An investor buys the stock of two companies, investing $10,000 in each. The stock of each company either goes up by 80% after a month (rising to $18,000) with probability  or drops by 60% (falling to...

An investor buys the stock of two companies, investing $10,000 in each. The stock of each company either goes up by 80% after a month (rising to $18,000) with probability
 or drops by 60% (falling to $4,000) with probability
. Assume that the changes in each are independent. Let the random variable
 denote the value of the amount invested after one month.

(a) Find the probability distribution of
.

(b) Find the mean value of
.

(c) Does the mean value represent the experience of the typical investor?