Statistics · Calculator companion · By K Imports
Mean, median & variation: practical guide
This guide explains how to use the Count.ie mean, median & variation. Compare average, range, population and sample variation. Follow the inputs, method and worked example below, then compare your own scenario.
Guide written .
Open the Mean, median & variation calculatorWhat to prepare
- Collect the underlying observations and state how they were sampled.
- Identify the population, sample size and relevant assumptions.
- Check whether observations, probabilities or measurements are independent where the method requires it.
Understand the inputs
- Numbers separated by commas or whitespace
- Up to 10,000 finite signed observations.
The calculation method
Population variance divides squared deviations by n; sample variance divides by n − 1.
Worked example
Illustrative inputs and their result.
Example inputs
- Numbers separated by commas or whitespace
- 10, 12, 14, 16, 18
Calculated example result
- Mean
- 14
- Median
- 14
How to interpret the result
A statistic summarises the supplied data; it does not repair biased sampling or establish causation. Uncertainty depends on the method's assumptions, not just the number of decimal places shown.
Compare equivalent datasets and report the sample size with the result. Where appropriate, test how an outlier or a different uncertainty assumption affects the conclusion.
Common mistakes to avoid
- Do not substitute population and sample definitions without checking the formula.
- Outliers, missing observations and selection bias can change the interpretation.
- A correlation or significance result is not proof of a causal relationship.
Assumptions and sources
A one-observation sample has no defined sample variance. This tool summarises numbers; it does not establish statistical significance.
If your case falls outside this scope, use a more suitable calculator or contact us about an unclear method.