expected value of coin selected from a drawer. Assume that the drawer contains 14 coins: 8 quarters, 2 dimes, and 4 nickels. One coin is randomly selected.
What is the expected value of the coin selected (in cents)?
i keep getting .1714.... and its wrong, it has to be right
2006-10-10 15:09:43 · 7 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
Joe C you were right, i have to enter it in as 17.14 in cents. its funny that all the other people were calling me dumb and they didnt know the right answer.
2006-10-10 15:23:44 · update #1
E=(8/14)(0.25) +(2/14)(0.10) + (4/14)(0.05)
= (2 + 0.2 + 0.2)/(14)
= 2.4 / 14
= 0.1714
The answer you keep getting is the same as mine. I think it's right.
2006-10-10 15:15:57 · answer #1 · answered by Anonymous · 0⤊ 0⤋
I assume we know the values of money.
The chance of picking a quarter is 8/14.
The chance of picking a dime is 2/14.
The chance of picking a nickel is 4/14.
To find expected value, multiply the value by the chance for each coin, and add all of these together.
(8/14)(.25)+(2/14)(.1)+(4/14)(.05)=expected value.
This is .171...
So you're correct, and your methods are probably correct as well.
Edit: Don't listen to the others. Expected value may yield a value that is not one of your options. Often, it does.
2006-10-10 22:15:37 · answer #2 · answered by zex20913 5 · 0⤊ 0⤋
what? a coin can only have one value, and no fractions... argue this case: the expected value would be 25 cents because the odds of drawing a quarter are greater than 50% by number and approximately another 10% by size... there ya go, expected value, 25 cents...
2006-10-10 22:15:09 · answer #3 · answered by Anonymous · 0⤊ 2⤋
You're right, but instead of 0.1714 I'd say 17.14 since the value is requested in cents, not dollars.
2006-10-10 22:17:31 · answer #4 · answered by Joe C 3 · 0⤊ 0⤋
Over half of the coins are quarters, so you should expect a quarter.
2006-10-10 22:49:15 · answer #5 · answered by Math geek 3 · 0⤊ 0⤋
Hmmm... I'm not sure... but.. how can you EXPECT a value other than 25 cents, 10 cents, or 5 cents?
2006-10-10 22:15:49 · answer #6 · answered by ♥Tom♥ 6 · 0⤊ 2⤋
how old are you cuz i get 25 cents because since there's more quarters your most likely to get a quarter and that equels 25 cents dumb dumb!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
2006-10-10 22:14:07 · answer #7 · answered by just ME 2 · 0⤊ 2⤋