Question

Check my work PLEASE
There are 9 red checkers and 3 black checkers in a bag. Checkers are selected one at a time, with replacement. Each time, the color of the checker is recorded. Find the probability of selecting a red checker exactly 8 times in 10 selections. Show your work.
Red checker: 9/12 = 3/4
Black checker: 9/12 = 1/4
(3/4)(3/4)(3/4)(3/4)(3/4)(3/4)(3/4)(3/4)(1/4)(1/4) = (3/4)^8 (1/4)^2
10C8 = 10!/ (8!2!)
= 10(9/2)
= 45
P(8) = 45 (3/4)^8 (1/4)^2
= 0.281568 = 28%

Answer 1

Binomial Probability Problem with n = 10 and p(red) = 12/15

P(x = 8) = C( 10, 8) * (3/4)^8 * (1/4) ^ 3

Answer 2

Let me crank that out and compare with your answer.

Answer 3

My equation is messed up. Sorry.

Answer 4

Binomial Probability Problem with n = 10 and p(red) = 4/5

P(x = 8) = C( 10, 8) * (3/4)^8 * (1/4) ^2

Answer 5

Revised Equation ^^^^^

Answer 6

Probability = .28156

Is that what you got?

Answer 7

Yes that's what I got too, thanks

Answer 8

.28156 Sorry, I left out the 1.

http://www.wolframalpha.com/input/?i=C(+10,+8)+*+(3%2F4)%5E8+*+(1%2F4)+%5E2

Answer 9

Alrighty, then.