Mean, median and mode are different ways of determining the average from a set of numbers. Range gives the difference between the highest and lowest values.
The mean takes the sum of all the values, then divides the total by the number of values given. The resulting average will not necessarily be equal to any of the values previously given and may contain a decimal. The mean is commonly taught as being the standard average.
The median is the middle value within a set of values arranged in numerical order. When a set has an even number of values, the median is determined by calculating the mean between the two most central values.
The mode is the number that is repeated most often within a set of values. If no numbers are repeated, then the set is determined to have no mode. A set can also have multiple modes if multiple numbers are equally repeated.
The range subtracts the smallest value from the largest value within the set. Range is useful to determine how spread out all the variables are. However, a single outlier within the set can affect the result in a way that does not accurately reflect the data.