A sample is one or more of a group, usually chosen according to some process, often so that the sample may be considered to be representative of the group. Sampling is the process of choosing samples.

Sample mean is calculated by dividing sum of observation with total number of observation in a sample. Mean is a type of average. It tells the general result of a sample.

Sample mean = sum of observations / total number of observations

If there are N number of observations for example; x

Sample mean = [x

Sample mean = sum of observations / total number of observations

If there are N number of observations for example; x

_{1}, x_{2}, x_{3},..., x_{N}, then the sample mean is calculated as;Sample mean = [x

_{1}+ x_{2}+ x_{3}+ ... + x_{N}]/ N