WAEC WAEC Nigeria General Mathematics

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(Statistics)

Mean, Median and Mode

Understanding Mean, Median, and Mode

What Are Mean, Median, and Mode?

In statistics, the mean, median, and mode are measures of central tendency that help us understand data distributions.

  • Mean: The average of a set of numbers, calculated by dividing the sum of all values by the number of values.
  • Median: The middle value in a data set when the numbers are arranged in order. If there is an even number of observations, the median is the average of the two middle numbers.
  • Mode: The number that appears most frequently in a data set. A set may have one mode, more than one mode, or no mode at all.

Calculating Mean, Median, and Mode

Mean

For a data set x1,x2,,xnx_1, x_2, \ldots, x_n, the mean xˉ\bar{x} is calculated as:

xˉ=x1+x2++xnn\bar{x} = \frac{x_1 + x_2 + \cdots + x_n}{n}

Median

  • Odd number of data points: The median is the middle number.
  • Even number of data points: The median is the average of the two middle numbers.

Mode

The mode is the value that appears most frequently in the data set.

Examples

Example 1: Find the Mean, Median, and Mode

Consider the data set: 3, 7, 7, 2, 5

Worked Example

Calculate the mean, median, and mode.

Example 2: Find the Median

Consider the data set: 8, 3, 5, 12

Worked Example

Calculate the median.

Tuity Tip

Hover me!

Tuity Tip: When calculating the median, always arrange the data in ascending order first!

Remember: The mode is not always present, and there can be more than one mode in a data set.

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