Calculate Percentile in Excel 2010

Question

This is my below list. I am trying to calculate 95% of calls came back in how many millseconds.

Milliseconds   Number of Calls
    45         14
    46               


        

Answer 1

An extra column would simplify the calculations but you can calculate without if you want......

Assuming milliseconds in A2:A21 and number of calls in B2:B21 you can use this array formula

=PERCENTILE(IF(TRANSPOSE(ROW(INDIRECT("1:"&MAX(B$2:B$21))))<=B$2:B$21,A$2:A$21),0.95)

confirmed with CTRL+SHIFT+ENTER

or this non-array version

=LOOKUP(SUM(B$2:B$21)*0.95,SUBTOTAL(9,OFFSET(B$1,0,0,ROW(B$2:B$21)-ROW(B$2)+1)),A$2:A$21)

I get a result of 63 with both - change to 0.75 (75th percentile) and you get 59