# Thread: Simple Bernoulli trial: prob of pipe failure during inspection

1. Originally Posted by tkhunny
Well, that was a Binomial Approximation. Is there a distribution that you feel might be more appropriate? Poisson? Beta? Weibull?
We haven't covered Poisson, Beta or Weibull in our syllabus yet; but I don't know whether the method you're using is the correct one as it is different from the approximation you suggested.

2. The only thing we didn't think about very much was the 23. We counted n = number of inspections. I began to wonder if we have a finite number of pipes and we should be counting n = number of pipes.

Since we correctly calculated the mean, let's try n*p = 9/23 again.

Since we can have as many inspections as desired, that may be considered infinite - quite inappropriate for the Binomial Distribution.
Since there are only six pipes, I guess, things should work out.

3. Originally Posted by tkhunny
The only thing we didn't think about very much was the 23. We counted n = number of inspections. I began to wonder if we have a finite number of pipes and we should be counting n = number of pipes.

Since we correctly calculated the mean, let's try n*p = 9/23 again.

Since we can have as many inspections as desired, that may be considered infinite - quite inappropriate for the Binomial Distribution.
Since there are only six pipes, I guess, things should work out.
Many thanks for yout help

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