Revision GuideStatistics & Data
Statistics Revision Guide
A fuller printable guide to descriptive statistics, centre measures, spread measures, and interpretation habits that help prevent misleading summaries.
Printable PDFOpen download
Worked Examples PackStatistics & Data
Worked Examples for Mean, Standard Deviation, and Z-Scores
A more substantial worked-examples pack for descriptive statistics and spread measures, designed for revision and checking.
Filename: worked-examples-for-mean-standard-deviation-and-z-scores.pdfFile size: 3 KB
Formula highlights
Mean
mean = sum of values / number of values
Z-score
z = (x - mean) / standard deviation
Example set 1: centre
Given a small dataset, compute mean, median, mode, and range, then compare what each measure notices and what it ignores.
Example set 2: spread
Use a compact dataset to calculate variance and standard deviation step by step, making the squared-deviation logic visible.
Example set 3: z-scores
Standardise a value using the mean and standard deviation, then interpret whether it is typical or unusual within the model.
Revision reminders
- Keep the centre and the spread conceptually separate.
- State whether the variance/standard-deviation model is sample-style or population-style if your workflow requires the distinction.
- Interpret results in context rather than quoting the number alone.
Related calculators
Use the formulas in live tools.
Featured
Mean Calculator
Calculate the arithmetic mean of a list of numbers when you want a quick measure of the dataset's average value.
Statistics & DataOpen
Standard Deviation Calculator
Measure how widely a dataset spreads around its average by calculating the standard deviation.
Statistics & DataOpen
Z-Score Calculator
Calculate how far a value sits from the dataset mean in standard-deviation units.
Statistics & DataOpen
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