views:

94

answers:

1

What should the percentile ranks be for each of these records and is there a MySQL query I can run to calculate the percentile for the score?

id    score   cumulative_score     percentile
1     100     100                  ?
2     50      150                  ?
3     25      175                  ?
4     25      200                  ?
5     10      210                  ?
+1  A: 

Generally, a percentile rank is the value of a variable below which a certain percentage of observations fall.

So, you don't specify if this is for "score" or "cumulative score," but for score, 80% of the observations fall below 100, 60% below 50, 20% below 25 and 0% below 10.

WhirlWind
So the guy who got a score of 100 is in the 80th percentile? I guess it's not possible to be in the 100th percentile as that would mean the score 100 was above 100% of all of the participants, which is not possible because the score 100 is included in all of the participants. Confusing!
Kirk
It just divides a distribution into 100 groups of equal (or approximately equal, depending on rounding) size, 0-99.
WhirlWind