A percentile, in plain English.
A theoretical percentile of 90 means about 90% of values fall below that point in the reference distribution. The remaining 10% fall at or above it. This is a mathematical comparison, not a claim about a particular group of people.
Check the calculation.
Subtract 100 from the score, divide by 15, then evaluate the cumulative standard normal distribution. For 130, z = 2 and the theoretical percentile is about 97.72%. The upper tail is 2.28%, approximately one value in 44.
The NIST statistical handbook explains the underlying distribution. The formula describes a reference model; it does not establish a population ranking for an uncalibrated test. Read our scoring methodology and limitations.