Z-Score 21.5: Complete Analysis

100.00%

Area Below

100.0

Percentile Rank

Above

Relative to Mean

Quick Interpretation

A z-score of 21.5 indicates that the value is 21.50 standard deviations above the mean. This means:

The value is quite unusual
Approximately 100.00% of values fall below this point
This score is at the 100.0 percentile

Detailed Explanation

When we say a z-score is 21.5, we're describing a point that is 21.500 standard deviations above the mean of a normal distribution. This helps us understand how unusual or common a value is compared to the average.

Real-World Examples

Example 1: Test Scores
If this z-score represented a test score, it would mean the student scored above average by 322.5 points (assuming a standard deviation of 15 points).

Example 2: Height
For adult male height (mean ≈ 5'10", SD ≈ 3"), this z-score would represent someone who is approximately 134.5 inches tall.

Common Uses

Field	Application
Education	Standardized test scores, grade distributions
Psychology	IQ scores, personality assessments
Medicine	Growth charts, lab results
Quality Control	Manufacturing specifications, process control