Measures of Location and Spread - Maths Edexcel Alevel Stats

A single value which describes a position in a data set

• Measure of location

• Measure of spread

• Modal class

• Data position

The mean can be calculated using the formula

• x̄ = ∑x/n

• x̄ = ∑n/x

• x̄ = x/∑n

• x̄ = n/∑x

The mean for a frequency table can be calculated using the formula

• x̄ = ∑x/n

• x̄ = ∑xf/f

• x̄ = f/∑f

• x̄ = n/∑f

Used when data is qualitative, or quantitative with either a single mode or two modes (bimodal)

• Mean

• Median

• Mode

• Range

Not very informative when each value only occurs once

• Mean

• Median

• Mode

• Range

Used for quantitative data

• Mean

• Median

• Mode

• Range

Used when there are extreme values, as they do not affect it

• Mean

• Median

• Mode

• Range

Used for quantitative data, and uses all the pieces of the data

• Mean

• Median

• Mode

• Range

Gives a true measure of the data

• Mean

• Median

• Mode

• Range

Affected by extreme values

• Mean

• Median

• Mode

• Range