Percentile Symbol - does it exist or not?

Question

Is there a standard symbol for percentile in mathematics, much like % is used for percentage? I have trying to get the right answer but only getting conflicting answers and logic.

Answer 1

As Neil mentions in his comment $P_i$ is a common notation to denote the $i$-th percentile.

The Wikipedia page on Percentile doesn't actually mention the notation as far as I can see but denotes quartiles as $Q_1$, $Q_2$, and $Q_3$ several times and from this it's logical that percentiles would be denoted by $P_i$ (and likewise other quantiles with their respective character in the same way).

A real world example of this notation (even if it's not subscript) is how you request percentiles in the Amazon CloudWatch API which follows the pattern p(\d{1,2}(\.\d{0,2})?|100) - or p5 for the 5th percentile, p70 for the 70th percentile, p50.36 for the 50.36th percentile, and p100 for the maximum value.

Answer 2

If you want to specify the vector (i.e. vector C) and the percentile (i.e. 95), then you may write: percentile(C,95).