Biostatistics for beginners: Measures of Dispersion

Calculating the range of a set of numbers is a straightforward process and is one of the simplest measures of dispersion in statistics. The range gives you an idea of how spread out the values in your data set are. Here’s how to calculate it: Identify the Highest and Lowest Values: First, you need to find the maximum (highest) and minimum (lowest) values in your data set. Subtract the Minimum from the Maximum: The range is calculated by subtracting the smallest value from the largest value. Range=Maximum Value− Minimum Value For example, let’s say you have a data set: 5, 7, 12, 20, 3, 15. The maximum (highest) value is 20. The minimum (lowest) value is 3. So, the range would be calculated as: Range=20−3=17 Thus, the range of this set of numbers is 17. Remember, while the range is easy to calculate and provides some information about the variability in a data set, it is sensitive to outliers. A single very high or very low value can dramatically affect the range, so it’s often used in conjunction with other measures of dispersion like the standard deviation or the interquartile range for a more complete understanding of a data set’s variability.