问题
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 33
47 40
48 41
49 83
50 114
51 124
52 82
53 89
54 99
55 82
56 72
57 80
58 101
59 73
60 74
61 81
62 64
63 70
64 61
What does above data means is-
14 calls came back in 45 milliseconds
33 calls came back in 46 milliseconds
40 calls came back in 47 milliseconds
etc etc
Now I am supposed to find out 95% percentile
from the above data. Meaning 95% of time, calls came back in this milliseconds.
Can anyone tell me how to do this in Excel Sheet? Thanks for the help
I am using Excel 2010. I have copied both the columns in my Excel Sheet as it is to calculate the percentage.
Update:-
With the below list, I am getting 95 percentil
e as 66. So that means 95% of time, calls came back in 66 milliseconds
which is not right I guess. It looks to me 95% of time, calls came back in ~4ms.
Milliseconds Number of calls
0 11
1 259
2 504
3 293
4 38
5 15
6 1
7 4
8 1
9 1
10 1
11 2
23 1
30 1
39 1
147 1
I am using this formula-
=PERCENTILE(IF(TRANSPOSE(ROW(INDIRECT("1:"&MAX(B$2:B$21))))<=B$2:B$21,A$2:A$21),0.95)
回答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
回答2:
Set up a new column which is "Number of Calls At or Below Time", and have it calculate the sum of the current row's number of calls, plus all numbers of calls in higher rows (lower times). Then, set up a column next to that called "Percentile", and calculate that by dividing "Number of Calls at or Below Time" by the total number of calls received. Whatever is the first row to show a percentile higher than 95% is the one which contains the 95th percentile.
回答3:
Get the standard deviation of the time in milliseconds field, and use that to (95% ~ 2 x std) count the number of calls below ~2 standard deviations?
来源:https://stackoverflow.com/questions/15671408/calculate-percentile-in-excel-2010