FORMULAS R HV LV STANDARD SCORE OR Z-SCORE IR Q Q z xx s s xx z 3 QD 1 IR 2 DD D9 D1 x x sz PD P90 P10 x x x x sz i n /xx/ n mad (x x) s s n 1 2 s 2 (x x) 2 n 1 s 2 s 2 (s) 2 QUANTILES - ROUND UP FOR THE POSITION D Q P K K K kn 10 kn 4 kn 100