16.13 : Microsoft Excel: Median, Quartile range, and Box Plots

In Microsoft Excel, calculating the median, interquartile range, and creating box plots can help understand the distribution of your data.

Median and Quartile Range: The median is calculated using the formula `=MEDIAN(range)', which provides the middle value of your data set. Quartiles divide your data into four equal parts. To find the first and third quartiles, use ‘=QUARTILE(range, 1)' and ‘=QUARTILE(range, 3)', respectively. The interquartile range (IQR), which measures data spread, is calculated as `Q3 - Q1`.

Box Plots: To create a box plot, start by calculating the median, quartiles (Q1 and Q3), and minimum and maximum values. This chart visually represents the median, quartiles, and potential outliers, providing a clear view of data spread and central tendency.

Box plots are particularly useful for identifying data skewness, variability, and outliers. The box shows the IQR of the data, and in the given example, the whiskers span the range of the data. However, in some cases when there are extreme values, outliers (shown as dots) may appear beyond the whiskers.This makes box plots a valuable tool for quickly summarizing the key characteristics of your data set in fields like statistics, quality control, or scientific research.