## Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y=4),

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### Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y=4),

Question :
Suppose X and Y are independent Poisson random variable , each with the mean 1 , obtain
i) P(X+Y=4)
ii) E[(X+Y)2]

zorro

Posts: 28
Joined: Sat Jun 12, 2010 9:26 am

### Re: Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y

zorro wrote:Question :
Suppose X and Y are independent Poisson random variable , each with the mean 1 , obtain
i) P(X+Y=4)
ii) E[(X+Y)2]

Martingale

Posts: 363
Joined: Mon Mar 30, 2009 1:30 pm
Location: USA

### Re: Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y

Martingale wrote:
zorro wrote:Question :
Suppose X and Y are independent Poisson random variable , each with the mean 1 , obtain
i) P(X+Y=4)
ii) E[(X+Y)2]

Thanks

so $\mu$ = $\lambda$ = 1

P(A+B=4) = ? stuck here !!!

zorro

Posts: 28
Joined: Sat Jun 12, 2010 9:26 am

### Re: Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y

zorro wrote:
Martingale wrote:
zorro wrote:Question :
Suppose X and Y are independent Poisson random variable , each with the mean 1 , obtain
i) P(X+Y=4)
ii) E[(X+Y)2]

Thanks

so $\mu$ = $\lambda$ = 1

P(A+B=4) = ? stuck here !!!

From the link I provided look at "Sums of Poisson-distributed random variables"

Martingale

Posts: 363
Joined: Mon Mar 30, 2009 1:30 pm
Location: USA

### Re: Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y

Martingale wrote:
zorro wrote:

Thanks

so $\mu$ = $\lambda$ = 1

P(A+B=4) = ? stuck here !!!

From the link I provided look at "Sums of Poisson-distributed random variables"

I couldnt understand how to evaluate P(A+B=4) as

is it P(A+B=4) = P(A) + P(B) = 4
or is it some other way

zorro

Posts: 28
Joined: Sat Jun 12, 2010 9:26 am

### Re: Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y

zorro wrote:
I couldnt understand how to evaluate P(A+B=4) as

is it P(A+B=4) = P(A) + P(B) = 4
or is it some other way

If X is poisson 1 and Y is poisson 1

then X+Y is Poisson 2

Martingale

Posts: 363
Joined: Mon Mar 30, 2009 1:30 pm
Location: USA

### Re: Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y

Martingale wrote:
zorro wrote:
I couldnt understand how to evaluate P(A+B=4) as

is it P(A+B=4) = P(A) + P(B) = 4
or is it some other way

If X is poisson 1 and Y is poisson 1

then X+Y is Poisson 2

but how should i represent it in my solution
P(A+B) = 1+1 = 2 but what about the '4'

I am having a hard time how to formulate this ? sorry or such silly questions?

zorro

Posts: 28
Joined: Sat Jun 12, 2010 9:26 am

### Re: Let X, Y, be ind. Poisson rand. vars; mean 1; find P(X+Y

zorro wrote:
but how should i represent it in my solution
P(A+B) = 1+1 = 2 but what about the '4'

I am having a hard time how to formulate this ? sorry or such silly questions?

I think you need to review the basics of probability before you start working with random variables. I really think it will help you since your foundation in the basics is not strong enough.

Good luck!

Martingale

Posts: 363
Joined: Mon Mar 30, 2009 1:30 pm
Location: USA