Find the value below which a given percentage of the data falls.
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=PERCENTILE.INC(A2:A100, 0.9)PERCENTILE.INC returns the value at a percentile (0.9 = 90th). It's used for SLAs, grading curves, and spotting top or bottom thresholds. Use 0.25 and 0.75 for quartiles.
=PERCENTILE.INC(ResponseTimes, 0.95)→42095% of responses are at or under 420 ms.
=PERCENTILE.INC({10,20,30,40,50}, 0.5)→30The 50th percentile is the median.
=PERCENTILE.INC({10,20,30,40,50}, 0.9)→46Excel interpolates between 40 and 50 when the percentile falls between two values.
Rank a value as a percentile
=PERCENTRANK.INC(A2:A100, B2)Returns where a value sits, as a percentile.
.INC includes the 0th and 100th percentiles; .EXC excludes them and needs more data points.
Use 0.25, 0.5 and 0.75 as the second argument, or =QUARTILE.INC(A2:A100, 1) for the first quartile.
As a decimal between 0 and 1. Entering 90 returns #NUM!.
In Excel 365 filter the data first: =PERCENTILE.INC(FILTER(B2:B100, A2:A100="East"), 0.9).
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