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## #1 2006-01-19 11:31:12

sandra
Guest

### Poisson distribution

i need some help on the following question......

The probability that a glass fiber will shatter during an experiment is believed to follow a poisson distribution. In certain apparatus, it was found that, on average, 7 glass fibers shattered. Determine the probability that, during a single demonstartion of the experiment,

i) two glass fibres will shatter

ii) at most two glass fibres will shatter

im finding it really difficult.

Thank you

## #2 2006-01-19 13:22:28

ryos
Power Member

Offline

### Re: Poisson distribution

Poisson? Isn't that french for "fish"?

Sorry, I don't have anything helpful to say.

El que pega primero pega dos veces.

## #3 2006-01-19 15:38:09

kempos
Full Member

Offline

### Re: Poisson distribution

1. P = (e^(-7)* 7^2)/2! = 0.02234121335

where 7 is expeted number of occurences and two the number of occurences we want to get.

2. P(0) + P(1) + P(2)

But I'm really not sure. Hope some guys here will be able to help you with this problem.

Last edited by kempos (2006-01-19 15:48:32)