Guavajuice
New member
- Joined
- Jul 4, 2020
- Messages
- 3
Hi!
I was doing this question on statistics, where I was given the joint probability distribution
f(x,y) = (9/16) (1/4^(x+y))
Where x and y were discrete random varaibles
x = 0,1,2,... And y = 0,1,2,...
I was then tasked to find E(X), E(Y) and Var(X) and Var(Y)
I managed to find E(X) and E(Y) =1/3, by finding sum to infinity for Geometric Progression for the y-term, and using an arithemtic-geometric progression sum to infinity to find the x-term.
However, when I was trying to find var(x)
I was stuck at this summation
Summation of x term , from x= 0 to x= infinity, of the function (x^2)/4^x
I'm not sure what kind of series this is, because, it doesn't seem to be an AP/GP/ or AGP, since the numerator is a square of X, while the denominator is an exponential function.
Any
I was doing this question on statistics, where I was given the joint probability distribution
f(x,y) = (9/16) (1/4^(x+y))
Where x and y were discrete random varaibles
x = 0,1,2,... And y = 0,1,2,...
I was then tasked to find E(X), E(Y) and Var(X) and Var(Y)
I managed to find E(X) and E(Y) =1/3, by finding sum to infinity for Geometric Progression for the y-term, and using an arithemtic-geometric progression sum to infinity to find the x-term.
However, when I was trying to find var(x)
I was stuck at this summation
Summation of x term , from x= 0 to x= infinity, of the function (x^2)/4^x
I'm not sure what kind of series this is, because, it doesn't seem to be an AP/GP/ or AGP, since the numerator is a square of X, while the denominator is an exponential function.
Any