Answer: $6,400
Step-by-step explanation:
The expected return is simply a weighted average of the different returns given their probability of happening.
If everything was invested in Project X, there is a 70% chance of success and 30% of failure. Payoff is $10,000 if successful and $2,000 if unsuccessful:
= (70% * 10,000) + ( 30% * -2,000)
= 7,000 - 600
= $6,400