Since there is a 70% chance of making $12,000 so have that:
.70 × 12000 = 8400
Also, we have a 10% chance of breaking even, so we also have that:
.10 × 0 = 0
Finally, we have a 20% chance of losing $7400 so we also have that:
.20 × 7400 = 1480
Thus, putting it all together we have:
.70(12000) + .10(0) + .20(7400) = 8400 + 0 + 1480 = 9880
Therefore, the expected value is:
$9880