# How to get Probability

1. Nov 12, 2008

### stunner5000pt

1. The problem statement, all variables and given/known data
Consider a random variable, defined to bethe sum of two random real numbers chosen uniformly from [0, 1]. Let the random variables X and Y denote the two chosen real numbers. Define Z = X + Y . Derive the cumulative density function and the probability distribution function

2. The attempt at a solution
Ok really this is a problem in the text and I don't understand how they get certain things

Let me quote the parts that make and dont make sense to me
So far so good

The figure they refer to has a square whose sides has length 1. The region E.8 is a right angle triangle located at the bottom left of the square whose side lengths are 0.8. Why is it E.8? What does that mean??

Ok why is that? First of all what is E.8 in the first place...?

Last edited: Nov 12, 2008