Help with poisson distribution

I have a solution and I hope it is right, lol.

X~Poi(n)

Given that the PMF of the Poisson dist is P(X = k) = (e^-n * n^k)/k! we can form a polynomial:

(e^-n * n^5)/5! = (e^-n * n^4)/4! + (e^-n * n^3)/3!
Multiply by 5!/e^-n to get:
n^5 - 5n^4 - 20n^3 = 0
Factorise
n^3(n^2 -5n - 20) = 0
Use quadratic formula and u get solutions
n = 0 (thrice), 7.623475 and a negative value.

The poisson dist has the requirement that the parameter, n > 0, so I would take n = 7.623475 as the solution (assuming I didn't make any silly mistakes).
 
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killari said:
I have a solution and I hope it is right, lol.

X~Poi(n)

Given that the PMF of the Poisson dist is P(X = k) = (e^-n * n^k)/k! we can form a polynomial:

(e^-n * n^5)/5! = (e^-n * n^4)/4! + (e^-n * n^3)/3!
Multiply by 5!/e^-n to get:
n^5 - 5n^4 - 20n^3 = 0
Factorise
n^3(n^2 -5n - 20) = 0
Use quadratic formula and u get solutions
n = 0 (thrice), 7.623475 and a negative value.

The poisson dist has the requirement that the parameter, n > 0, so I would take n = 7.623475 as the solution (assuming I didn't make any silly mistakes).
Click to expand...
Yeh thats right.. Thanks for the help :D
 
Sinque said:
I'm with you here. How can a knife be dangerous with a young child? Silly people!

But you drink a litre of spirits a week so I bet you're 'ard.
Click to expand...

Christ, why do people.
A. Assume all kids carry knives.
B. Assume the kids will actually use the knives
C. Assume the ones who use the knives know how to use them

It's easy enough, I'll explain this once, if a 13 year old kid pulls a knife on you, just kick them hard in the nuts.
You now no longer have to live your life in fear, allowing little scummy ****ers off the estate disrespect you.

Also a bottle a week isn't much, you're taking it out of context of the thread when I mentioned it, I have a couple of glasses of whisky of an evening, it's the same as someone enjoying a bit of cheese or a cigar. I'm sure you never treat yourself with a beer or a glass of wine in front of the telly.
 
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