Finding the Median
The median is a central measure that represents the middle value of a dataset, providing insight into the data's tendency. For ungrouped data, the median is straightforward to calculate by arranging the data in ascending order and finding the middle value. However, when dealing with grouped data, calculating the median involves understanding cumulative frequencies and locating the median class. This section details the process of calculating the median from both ungrouped and grouped data, illustrating its significance in statistical analysis.
Steps for Finding the Median in Grouped Data:
- Construct a Cumulative Frequency Table: This table helps to identify the class that contains the median.
- Identify the Median Class: Find the cumulative frequency that's greater than or equal to n/2 (where n is the total frequency).
- Use the Median Formula: The median can be calculated using the formula:

Where l = lower limit of the median class, cf = cumulative frequency of the class before the median class, f = frequency of the median class, and h = class size.
- Interpret the Median: Understand that the median gives the point that divides the data into two equal halves.