Statistics versus Parameter
Let’s assume from the scenario illustrated here, that the average income of all the customers is $1,300/month. Given that this amount is calculated from the sample drawn from the population, it is called a Statistic or Sample Statistic.
If you follow the assumptions rightly, then we can generalize this result to the whole population, thus the average income of all the customers in the country is $1,300.00 and this is known as the Parameter or the Population Parameter. In statistics, it is rare to obtain the parameter from a real population in a study. Hence, we use the statistic to make inferences about the general population.