---
id: Z-score
aliases:
  - Z-score - An example
tags: []
---

### Z-score - An example

- John gets a mark of 64 in a physics test, where the mean is 50 and the
  standard deviation is 8.
- Jane gets a mark of 74 in a chemistry test, where the mean is 58 and the
  standard deviation is 10

Who has a better class performance?

- John's z = (64 - 50) / 8 = 1.75
- Jane's z = (74 - 58) / 10 = 1.6
- Although Jane's score is higher, John's score is further above the mean, and
  it might be concluded that John has achieved greater success.