# Find the probability distribution....

• Jan 7th 2012, 11:10 AM
Wevans2303
Find the probability distribution....
Tv's are manufactured in lots of 200, 9 of these are tested and if none are faulty then the lot is accepted, find the probability distribution of the number of faulty televisions assuming there are 20 in a lot.

Help :/ (Thinking) Is this the poisson distribution?
• Jan 7th 2012, 01:54 PM
matheagle
Re: Find the probability distribution....
Sounds like a hypergeo
But it seems that you want the distribution of the number of bad tvs selected

$\displaystyle P(X=x)={{20 \choose x}{180\choose 9-x}\over{200\choose 9}}$

where x=0,1,...9.
That took forever to type on a lame ipad with a lousy connection at an airport.
• Jan 8th 2012, 01:43 AM
Wevans2303
Re: Find the probability distribution....
Quote:

Originally Posted by matheagle
Sounds like a hypergeo
But it seems that you want the distribution of the number of bad tvs selected

$\displaystyle P(X=x)={{20 \choose x}{180\choose 9-x}\over{200\choose 9}}$

where x=0,1,...9.
That took forever to type on a lame ipad with a lousy connection at an airport.

Thank you.

I really need to sharpen up on identifying which distribution it is. Any tips?
• Jan 8th 2012, 06:55 AM
matheagle
Re: Find the probability distribution....
you do know how to get to carnegie hall?
practice practice practice
• Jan 8th 2012, 07:17 AM
Wevans2303
Re: Find the probability distribution....
Quote:

Originally Posted by matheagle
you do know how to get to carnegie hall right?
practice practice practice

Haha, practice I must and practice I will. ;)
• Jan 8th 2012, 07:29 AM
ILikeSerena
Re: Find the probability distribution....
Quote:

Originally Posted by matheagle
That took forever to type on a lame ipad with a lousy connection at an airport.

I'm guessing that at least it gave you something to do while waiting.

Quote:

Originally Posted by matheagle
you do know how to get to carnegie hall right?
practice practice practice

:D