Chi-square distribution comes under the category of continuous probability distribution. It was first introduced by the Helmert  and then re-modified and introduced by Karl Pearson .
The Chi-square distribution can be mathematically defined as follows:
and ν is called the degree of freedom. The xi are normally and independently distributed with means μi and SD σi.
It is denoted by the Greek letter χ2 [chi-squared].
Let X be a normally distributed random variable with mean μ and SD σ.
Let us draw a large number of independent random samples of size n from this population. Convert each value of xi within ...