Orji Anyianuka

There are two types of statistics: descriptive and inferential statistics. Organizing, summarizing, and presenting data in an informative way is usually referred to as descriptive statistics. For example, Nigeria’s population is usually reported as 200 million people. This information is descriptive statistics. It is also descriptive when we calculate the percentage growth from one year to another. However, it would no longer be descriptive if we want to use the current population figure and the yearly percentage growth to estimate the population in the next ten years because we are no longer summarizing past populations but estimating future populations. 

The main interest in inferential statistics is finding something about a population from a sample taken from that population. Oftentimes statisticians are not able to study a total population, so they study a sample of that population and then make a smart guess of the total population based on the results obtained from the sample.  The method used to estimate a property of a population on the basis of a sample is called inferential statistics.