Two Random Variables
Introduction In the previous post of Basic Probability , I discussed my chance of visiting Paris next year. I had a sample space like this: \( S = \{Meet, No\_more\_holiday, No\_money, Paris\_gone\_from\_Earth, ...\} \). The random variable of \( X \) was all about me going to Paris next year. What I am going to write in this post is when we have two sample spaces, two outcomes and two random variables. Having two random variables means that we need to consider the followings: two events happen simultaneously ( joint probability ), only one event happens regardless of the other event ( marginal probability ) and one event happens because of the other event ( conditional probability ). Let's define a simple sample space of me visiting Paris next year is \( S_X = \{me\_in\_paris, me\_not\_in\_paris\} \). Let's define another sample space to have two events at the same time. The second event is whether Emily goes to Paris next year. We now have anot...