Average

Definition

The average, or mean, is the sum of a set of values divided by the number of values. It provides a measure of central tendency for the data.

5 Must Know Facts For Your Next Test

1. The formula for calculating the average is $\bar{x} = \frac{\sum x_i}{n}$ where $x_i$ represents each value and $n$ is the number of values.
2. Average is sensitive to extreme values or outliers, which can skew the result.
3. In a symmetric distribution, the mean, median, and mode are all equal.
4. The average can be used for both sample data and population data, but notation differs: $\bar{x}$ for sample mean and $\mu$ for population mean.
5. Understanding average helps in comparing different sets of data and summarizing datasets.

Review Questions

• What is the formula to calculate the average?
• How does an outlier affect the average?
• In what type of distribution are the mean, median, and mode equal?

Related terms

Median:

The middle value in a sorted dataset; it separates the higher half from the lower half.

Mode:

The value that appears most frequently in a dataset.

Outlier:

A value significantly higher or lower than most other values in a dataset.