Tutoring statistics, you help students who, in many cases, are facing completely new ideas (to them).  The tutor continues his goal of explaining statistics from a “day-to-day” point of view.

In an introductory stats course – which is probably as far as most people ever need to take it – probability is often the first topic.  You might continue with it for a few weeks even, without hearing of the normal distribution.  However, the normal distribution will almost always turn out to be the main focus of the course.

The normal distribution is the “bell curve” some people refer to.  Any large population follows it; therefore, the normal distribution is very useful in big business and for government.  People who are studying stats towards a professional career (rather than just for academic reasons) get schooled in the normal distribution because of its practical application.

A population that follows the normal distribution (virtually all do) is called a normal population.  Such a population follows some predictable traits which are very useful to know:

1. The mean cuts the population exactly in half:  50% lies below it, the other 50% above.
2. 68% of the population lies within one standard deviation of the mean. For example: if the mean is 100 and the standard deviation is 20, 68% of the population lies between 80 and 120.
3. 95% of the population lies within two standard deviations of the mean. To follow along with the population mentioned above, 95% of it will lie between 60 and 140.

I’ll be continuing with implications of the facts above – as well as more attributes of the normal distribution – in coming posts. Cheers.

Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.