Statistics: Discrete Random Variables

A random variable, usually written X, is a variable whose possible values are numerical outcomes of a random phenomenon. The difference between a random variable and a probability is that a random variable is a possible value that the target phenomenon takes, and a probability is an assigned value that is how likely it is to happen for each possible value(a random variable). For example, I will show you two cases using a die. We denote the range of a random variable by the letter S with a subscript, which is the name of the random variable, so Sₓ in this blog, and a probability as P(X). <ul> <li>Case 1: a fair die with 1, 2, 3, 4, 5, and 6 values</li> </ul> We assume this die is fair and will produce each value uniformly. As you can see in the figure below, this die can only take 1 to 6 values, so the range of random variables is {1,2,3,4,5,6}. A probability is assigned in equal because of a fair die. <a href="https://medium.com/intuition/statistics-discrete-random-variables-68dc2e21458d">Website</a>