1. Average refers to the sum of numbers divided by n. Also called the mean average.
Average Formula = Sum of observations/ Number of observations
Some important properties of average are:
When the difference between all the items is same (and the number of terms is odd), then the average is equal to the middle term.
2. Suppose a man covers a certain distance at x kmph and an equal distance at y kmph. Then, the average speed during the whole journey is (2xy/x+y) kmph.