Posted by **Jack** on Wednesday, May 2, 2012 at 7:16pm.

Through a mix up on the production line, 5 defective light bulbs were shipped out with 32 good ones. If 4 are selected at random, what is the probability that at least 3 of them are defective?

- Probability Math -
**MathMate**, Wednesday, May 2, 2012 at 11:07pm
This typically calls for the hypergeometric distribution, which gives

P(y)=[(r,y)(N-r,n-y)]/(N,n)

where

N=total 32+5=37 light bulbs

n=sample size of 4

r=defective out of N, 5

y=number of defective in the sample

(x,y)=combination=x!/(y!(x-y)!)

P(3)=[(5,3)(37-5,5-3)]/(37,5)

=4960/435897

P(4)=160/435897

Total P(3+)=5120/435897=1.17%

## Answer This Question

## Related Questions

- math prob. - Through a mix-up on the production line, 6 defective refrigerators ...
- Math - A firm manufactures light bulbs and those that come out of the assembly ...
- Statistics - A box contains 12 lights bulbs, of which 4 are defective. All bulbs...
- Probabilities - Need some help please! A box contains four good light bulbs and ...
- Probability - A company produces light bulbs, and finds that approximately 2% of...
- math - A manufacturer of light bulbs knows that 3% of the production of their ...
- math - A manufacturer of light bulbs knows that 3% of the production of their ...
- math - One light bulb is selected at random from a lot of 150 light bulbs, of ...
- Probability - In large lot of electric light bulbs 5% of the bulbs are defective...
- Maths - In a large lot of electric light bulbs,5% of the bulbs are defective....

More Related Questions