Statistics
Mean
The arithmetic average of a set of numerical values, calculated by summing all values and dividing by the total count.
What is Mean?
The mean is a measure of central tendency that represents the 'center of gravity' of a distribution. It is highly sensitive to the exact value of every score in the dataset.
Why Mean Matters
The mean provides a single summary value for continuous data and forms the mathematical basis for many advanced statistical tests like t-tests, ANOVA, and regression.
Example
To find the mean test score of a class of 20 students, the teacher adds all 20 scores together and divides the sum by 20.
Common Mistakes
- Using the mean to summarize highly skewed data, where it can provide a misleading picture of the 'typical' observation.
- Calculating the mean of ordinal or categorical data, where the intervals between numbers are not necessarily equal.