Statistical calculations often appear mystical as though plucked from mid-air. Statistical calculations are in fact based on the mathematical pattern of events. These mathematical patterns are called distributions.
Example of statistical distributions are:
There are many other statistical distributions; however, here let us here look at the binominal and Normal distributions.
When you flip a coin there are two possible outcomes; they are either heads or tails. So, when you fillip a coin and take the tally of all the ‘heads’ and ‘tails’ what you have is a binominal distribution.
Normal distribution is also called Gaussian distribution. Many natural phenomena follow a Normal distribution. For example, if you plot the height of all the boys in a class on the x-axis and the frequency on the y-axis, you will get a bell-shaped curve. The x-value of the peak of the bell-shaped curve corresponds to the mean (i.e. average) height. The mathematical pattern of the bell shape gives rise to many of the statistical calculations we often undertake in medical research.