Median
The "median" is another way to find the middle of a set of numbers, but instead of blending them, it points to the value that sits right in the center once the numbers are lined up in order.
To find it, first sort your values from smallest to largest. If you have an odd count of values, the median is the single one in the exact middle. If you have an even count, there are two middle values, so you take their mean (add them and divide by two) to get the median.
The big advantage is that the median isn't thrown off by extreme values. A project manager reaches for it when the data has outliers — say, one task that took wildly longer than the rest — because the median still reflects the "typical" case honestly, while the mean might get distorted.
Think of it like lining up a group of people by height and pointing at the person standing dead center. It doesn't matter if the tallest person is a basketball star towering over everyone — the person in the middle still represents the typical height of the group.
Take these five task durations: 4, 6, 5, 9, and 6 days. First sort them: 4, 5, 6, 6, 9. With five values, the middle one (the third) is 6, so the median is 6 days. Now suppose one task had actually taken 90 days instead of 9: sorted, that's 4, 5, 6, 6, 90, and the median is still 6 — showing how the median stays steady even when one value is extreme, whereas the mean would jump to 22.2.
Every PMP formula explained free — plus worked examples and practice in PMP Math, and full timed mocks in the simulator.