Mean is just another name for average. To find the mean of a data set, add all the values together and divide by the number of values in the set. The result is your mean! To see an example of finding the mean, watch this tutorial!
The mean and median can help you better understand a data set. Check out this real world example involving finding and comparing the mean and median of multiple data sets.
When you're trying to learn about a population, it can be helpful to look at an unbiased sample. An unbiased sample can be an accurate representation of the entire population and can help you draw conclusions about the population. This tutorial introduces you to unbiased sampling!