Find the value at any percentile rank in a dataset using linear interpolation.
A percentile indicates the value below which a given percentage of observations fall. This calculator uses the R-7 linear interpolation method, consistent with Excel's PERCENTILE.INC.
Index = (p/100) × (n − 1); interpolate between adjacent values
It means 90% of the data values fall at or below this value.
Yes — Q1 is the 25th percentile, Q2 the 50th, and Q3 the 75th percentile.