Measures of Spread

What are the measures of spread?

This post will help you understand the terms involved in describing the measures of spread in Prelim Standard Math. A measure of spread is calculated to determine whether the scores are close together or spread apart. Three measures help us identify these. The range is the difference between the highest score and the lowest score. The interquartile range involves dividing the data into four equal parts and using the interquartile range formula to determine how spread out the data is. Standard deviation is a measure of spread about the mean. 

What are the measures of spread?

The video below explains the different measures of spread in more detail and the formulas used.

How to calculate the range of data

The following video explains how to find the range of the data and advantages and disadvantages of using the range as a means of measuring spread.

How to use the interquartile range to measure the spread.

The following videos will help you understand the interquartile range formula and how it is useful to measure the spread.

Part 1

Part 2

How to find the standard deviation

The videos below will help you understand what standard deviation is and how to work it out using your calculator.

Part 1

Part 2