let me define a new random variable Q, let me define a new random variable Q that is equal to you essentially sampling from this standard normal distribution and squaring whatever number you got. so it is equal to this random variable X squared, it is equal to that random variable X squared the dist for this random variable right here is going to be an example of the chi-squared distribution, actually what we are going to see in this video is that the chi-squared distribution is actually a set of distributions depending on how many sums you have right now we only have 1 random variable that we are squaring so this is just one of the examples that we will talk more about them in a second. 