- #1
Karebear
- 9
- 0
Homework Statement
If you throw exactly 1 head in three tosses of a coin you win $27. If not you pay $21.
Homework Equations
I know, E(X) = sum[x subscript i * P(X = x subscript i)]
The Attempt at a Solution
Sorry y'all I don't really know how to use all the fancy letters and signs on here, but I'm tryin.
OK so, I get stuck at the very beginning of the problem trying to find P(X = x)
Here is what I have:
Possible Outcomes:
x = # of heads: P(X=x)
0 1/8 = 0.125
1 3/8 = 0.375
2 ?
3 ?
My problem is that I don't really understand why the P(X=x) for 0 heads is 1/8 I know I should, I just can't seem to remember and I'm getting frustrated which is making everything harder. I do understand that there are 8 possible outcomes b/c 2 sides to a coin and 3 tosses so 2^3 = 8