What is the z-score of a test score of 85 when the mean is 80?
A z-score measures a data point in standard deviation units: how far it sits from the mean, and in which direction.
Try this lessonFind the step that makes it click.
Pick a topic in math, science, chemistry, or writing. Try an example, get a clue, and practise at your pace.
No account or card needed. Practice answers stay on this page and aren’t saved.
1 lesson for “Z-scores”
Try a step. See what clicks.
Work through an example, ask for a clue when you need one, then try a new question on your own.
Browse by subject
All of math, science, chemistry and writing lessons or search across the whole library above.
Learn by trying
Fill in one step at a time and check your answer. Need help? Tap “Give me a clue.”
Treat these examples as a starting point for a conversation, not as a replacement for your teacher’s guidance.
Need help with your own question? See how the family service works