General purpose of this lecture is to present on Mean, Median, Mode and Range. Mean – the average of a group of numbers. Median – the middle number in a set of ordered numbers. Mode – the number that appears most frequently in a set of numbers. Range – the difference between the greatest and the least value in a set of numbers. The “mode” is the value that occurs most often. If no number is repeated, then there is no mode for the list. The “range” is just the difference between the largest and smallest values.