Published: 02 Jul 2019

**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.

- If x is added to all the items, then the average increases by x.
- If x is subtracted from all the items, then the average decreases by x.
- If every item is multiplied by x, then the average also gets multiplied by x.
- If every item is divided by x, then the average also gets divided by x.

**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.

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