Biostatistics

13.18 CHI-SQUARE DISTRIBUTION

Chi-square distribution comes under the category of continuous probability distribution. It was first introduced by the Helmert [1875] and then re-modified and introduced by Karl Pearson [1900].

The Chi-square distribution can be mathematically defined as follows:

and ν is called the degree of freedom. The x_i are normally and independently distributed with means μ_i and SD σ_i.

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 x_i within ...