Friday
May 24, 2013

Homework Help: algebra

Posted by Liz on Tuesday, May 15, 2012 at 6:52pm.

Will you please check my work for me? Thsnk you!

There are 12 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 7 times in 10 selections. Show your work.
P(success)=P(red)= 12/15= 0.8
n=7 r=5
10C7= 10!/(10-7)! = 10!/3! = 10*9*8*7*6*5*4*3!/ 3!= 10*9*8*7*6*5*4= 604,800
P(red7times)= 10C7 (0.8)^7(0.2)^3
= 604,800 (0.8)^7(0.2)^3
= 604,800 (0.2)(.008)
= 604,800(0.0016)
=967.68

• algebra - Anna, Tuesday, May 15, 2012 at 7:22pm

You are correct.

• algebra - Liz, Tuesday, May 15, 2012 at 7:26pm

Thank you Anna! How did you figure that out and what grade are you in?

Related Questions

Algebra - 3. There are 12 red checkers and 3 black checkers in a bag. Checkers ...
math - in each game there are 12 red checkers and 12 black checkers.If tom put ...
math - a bag contains 12 black checkers and 12 red checkers. What is the ...
Algebra2 {ASAP} - Hi helper, I used permutation for the following question. How ...
math - What is the probability of drawing a red checker from a bag of 9 black ...
math - drawing a black checker from a bag of 9 black checkers and 6 red checkers...
math - A bag contains 7 red checkers and 11 black checkers. One checker is drawn...
math - State whether the events described are independent or dependent and ...
math 8 - A square array of checkers contains 121 checkers How many checkers are ...
math - a checkerboard has 8 squares on a side. at the beginning of a game of ...