i have a question, if possible, I need some one to help me to solve it. I know it's easy but it kind make me dizzy.
if a cable is manufactured with probability of 0.001 that has one blemish per foot and probability of 0 for more than a blemish with same length. If X is the number of blemish per 3000 feet, get the Pr(X=5) ??
is the solution will be as follow:
mu = n * p = 3000 * .001 = 3
Pr(X=5) = [ 3^5 * e^(-3) ] / 5! = .100 =10% (Poisson Distribution)
Poisson is a discrete distribution, therefore the values can only be integers, 1,2,3 etc. are the values from 0..5. are the values 0..4.
This implies that .
The tables that I use are Poisson statistical tables. They are basically a shortcut for working out probabilities without doing the calculations. If your course does not use them though, then I do not recommend using them, as this could have a negative affect when you come to do the calculations the the exams and you've not a clue how to do them
From what I've seen though you seem to have got to grips with the distribution quite fine.