Answer:
The expected value of the proposition is $2.50.
Explanation:
When a coin is tossed two times, the following is the sample space (S)
S = {HT,TH,TT,HH}
Using the information in the question, we can derive the following win/loss table:
S     Probability      Payoff
TH Â Â Â Â Â Â 1/4 Â Â Â Â Â Â Â Â Â Â Â -$30
HT Â Â Â Â Â Â 1/4 Â Â Â Â Â Â Â Â Â Â -$30
TT Â Â Â Â Â Â 1/4 Â Â Â Â Â Â Â Â Â Â Â -$30
HH Â Â Â Â Â 1/4 Â Â Â Â Â Â Â Â Â Â $100
The expected value (E) can now be calculated as follows:
E = Sum of (Probability * Payoff) = (1/4 * ($-30)) * (1/4 * ($-30)) * (1/4 * ($-30)) = (1/4 * $100) = ((1/4) * (-30)) + ((1/4) * (-30)) + ((1/4) * (-30)) + ((1/4) * 100) = $2.50