Thread: Discrete Random Variables

Hi. Glad to see that we're being reminded of the rules. Here's a question on random variables.

The discrete random variable X has a probability density function



P(X=x) is 0 otherwise


If denotes the sum of two independent observations of
Determine the value of

Originally Posted by I-Think

The discrete random variable X has a probability density function
P(X=x) is 0 otherwise
If denotes the sum of two independent observations of
Determine the value of

Note that elementary event Y=4 is simply {(1,3),(3,1),(2,2)}.
Calculate the probabilities of each and add.

Silly statistician, integration is for continuous random variables.

Sorry about this question, for some strange reason I thought this was a continuous random variable, and continued in this erroneous belief even after your help.

Oh well, everybody makes mistakes in life, and maths.

Thanks for your help. (Please don't remind me of the thread's title)