This sample demonstrates three statistical distributions: Normal distribution, T Distribution (also called Student’s distribution) and F Distribution.

The Distribution cumulative function is shown as a background picture. The red area represents the selected probability percentage of area below the distribution function, and can be symmetric to the mean of distribution (called two-tailed probability).

Normal distribution does not have a degree of freedom. T distribution (i.e. Student’s distribution) has one degree of freedom while F distribution has two degrees of freedom.