Median: 5 Mistakes to Avoid
Finds the middle value of a list. The maths is not complicated, but a handful of errors come up again and again in this and related math & geometry calculations. Here is what to watch for.
Each formula has assumptions built in. Area formulas assume flat shapes, volume formulas assume regular solids and statistical measures assume the data you enter is the data you want to describe. Knowing the assumptions helps you pick the right tool.
Calculators are best used to check working rather than replace it, especially for exams where method marks count. Work the problem by hand first, then confirm with the calculator.
1. Forgetting the order of operations
Powers and brackets come before multiplication and addition.
2. Confusing radius and diameter
Many circle formulas use the radius, which is half the diameter.
3. Mixing units
Measurements must all be in the same unit before applying the formula.
4. Population versus sample formulas
Sample standard deviation divides by n − 1; population divides by n.
5. Using the wrong percentage base
A percentage change is measured against the original value, not the new one.
The correct method
Sort the values; take the middle one (or the average of the two middle values).
For example, with these inputs:
- Numbers (separated by commas): 12, 15, 9, 22, 15, 30
the calculator returns:
- Median: 15
Related calculations
- Volume of a Hemisphere Calculator: Calculates the volume of a hemisphere from the measurements you enter.
- Surface Area of a Cube Calculator: Calculates the surface area of a cube from the measurements you enter.
- Surface Area of a Cuboid Calculator: Calculates the surface area of a cuboid from the measurements you enter.
- Surface Area of a Sphere Calculator: Calculates the surface area of a sphere from the measurements you enter.
The Median Calculator applies the formula consistently, so it is a quick way to double-check your own working.
Run your own numbers: Median Calculator