You are here:

Excel/calculate a probability using excel functions


I am trying to figure out how to calculate a probability using the function command in excel and i am drawing a blank.

I have a mean of 23.4,standard deviation of 9.05079 and am trying to get the probability of a number coming out between 17.2952 and 29.5048.

I thought Norminv function would work ,but no-good...........

I would appreciated any help,I am not a stat's person so,I could
be doing this backward altogether.....


Joseph Z Ward


We know that on the standard normal distribution, the area between -1.96 and +1.96 includes an area (probability) of .95.  Recall that for the standard normal, the mean is zero and the standard deviation is 1.

so to test the approach I use the formula


so I get the cumulative area from minus infinity up to 1.96 and then subtract the cumulative area from minus infinity up to -1.96

I can use the same approach for you problem.


give a probability of  0.50000947370046

since each of your end points are .674504656  from the mean, then this would include approximately the middle 50%.  

Note in Excel 2010, Microsoft introduced a standard naming convention for statistical functions.  While you can use the above, the new way would be:


so there is a period between "NORM" and "DIST" =  NORM.DIST

I don't  have Excel 2010 installed here so I can't test that.  But if you run into problems, the old functions are still supported.

Tom Ogilvy  
About Excel
This topic answers questions related to Microsoft Excel spreadsheet (or workbook) stand-alone or Mircrosoft Office Excel including Excel 2003, Excel 2007, Office 2000, and Office XP. You can get Excel help on Excel formulas(or functions), Excell macros, charting in Excel, advanced features, and the general use of Excel. This does not provide a general Excel tutorial nor the basics of using a spreadsheet. It provides specific answers to using Microsoft Excel only. If you do not see your Excel question answered in this area then please ask an Excel question here


All Answers

Answers by Expert:

Ask Experts


Tom Ogilvy


Selected as an Excel MVP by Microsoft since 1999. Answering Excel questions in Allexperts since its inception in 2001. Able to answer questions on almost all aspects of Excel's internal capabilities. If seeking a VBA solution, please specify that in your question itself so I give you the answer you want. [Excel has weak protection - if you are distributing an application, I don't answer questions on how to protect your project from your users.]


Extensive experience.

Master of Science (MS) degree Operations Research (ORSA)

Awards and Honors
Microsoft MVP in Excel.

©2017 All rights reserved.

[an error occurred while processing this directive]