The mean is certainly one of the most used values to describe a sample or a dataset. It is often called average and constitutes one of the measures of the central tendency of your sample.

The mean is the sum of all the values in your dataset divided by the number of values in the set.

In R, the function that calculates the mean is called mean():

my.dataset <- c(1,2,3,4,5,6,7,8,9,10)
mean(my.dataset)
## [1] 5.5