Percentile calculation

[matjeng]

Hi guys!

I have a problem finding the percentile (0.1,0.5,0.9) of my bell curve in excel. Wonder if someone could help out. The data looks something like this:


Size Volume (%)
100 0
200 1
300 0


Any help would be appreciated

[Glenn Kennedy]

Percentiles aren't difficult.

if you have a range of values in (say) A1:A15...
=PERCENTILE(A1:A15,.9)

gives you the 90th percentile. However, I'm a wee bit confused by the data example that you have shown. Can you upload a larger sample?

[matjeng]

Hi Glenn,

I have tried using that formula before but doesn't work.

Check out the attached file. Im expecting values in size.

[Glenn Kennedy]

It's the zeros that are your problem. Delete them to leave NOTHING and the percentile works perfectly.

[Glenn Kennedy]

I think that I may have misunderstood your request. If it's the percentile of the SIZE that you want, refer to the attached sheet.

[matjeng]

Not that simple mate. The 0.1 should be 4.425, 0.5 = 35.927 (yes I have the answer just need to put it in excel)

[MrShorty]

What definition of "percentile" are you using to get those values? They don't seem to fit the usual definitions I'm used to for percentile, so I cannot see how you come up with those results.

[Glenn Kennedy]

Thanks (again) Mr Shorty. I've been puzzling over exactly what definition of percentile the OP has been using. I spend too much time playing with numbers & can't see what the OP is after...

[matjeng]

Seems like I have to figure out the mathematics behind it first. Thank you guys for helping out.

[Glenn Kennedy]

I was thinking about this again. Have you a set of raw data that you have attempted to fit to a normal distribution (bell curve)? That's what we need to see - not the fitted data.