# Thread: Probability question

1. ## Probability question

Dear Forum , I having issues with the following any feedback would be appreciated..

Two coins are flipped. You win $2 if either 2 heads or 2 tails turn up; you lose$3 if a head and a tail turn up? What is the expected value of the game?

thanks -AC 360-

2. Originally Posted by AlgebraicallyChallenged
Dear Forum , I having issues with the following any feedback would be appreciated..

Two coins are flipped. You win $2 if either 2 heads or 2 tails turn up; you lose$3 if a head and a tail turn up? What is the expected value of the game?

thanks -AC 360-
HH win $2 TT win$2
HT lose $3 TH lose$3

Each outcome has probability of .25

Expected value$\displaystyle =.25*2+.25*2+.25*-3+.25*-3=-.5$

3. ## Expected Value

The formula for this type of questions is

$\displaystyle E(X)=\Sigma{xP(X)}$

You need to conduct 3 steps
1) List each possible event
2) State the probability of each event occurring
3) State the outcome associated with each event

Event:2H 1H1T 1T1H 2T
Prob.: 0.25 0.25 0.25 0.25
Outcome: +2 -3 -3 +2

Use the formula:$\displaystyle E(X)=\Sigma{xP(X)}= 0.5-0.75-0.75+0.5$
$\displaystyle E(X)=-0.5 dollars$