Bell Curve in MS Excel With Only Three Numbers (25%tile, 50%tile, and 75%tile)

Posted on 2015-01-20
Last Modified: 2015-01-27
Hi, Can somebody detail how to create Bell Curve charts in MS Excel 2013 when given only three sets of #s - the 25th percentile numbers, the 50th percentile numbers, and the 75 percentile numbers ?   Based on a Z-table of entries the 25th percentile is at -.67 standard deviations and the 75th percentile is at .68 standard deviations from the mean (if I am reading this correctly, I am a bit rusty at this though).  The goal is to create the Bell Curve charts in order to determine what the 90th percentile scores or what any other percentile scores would be when given the 25th, 50th, and 75th percentile scores (that is to say, have the Bell Curve charts complete the scale based on the given 25th, 50th, and 75th percentile inputs).  TIA ...
Question by:LGroup1
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 3
  • 2

Expert Comment

ID: 40561409
If you upload a dummy data WB, then I eould create the chart

Author Comment

ID: 40562269
Thanks. This is an example of the data that is available:  25% = 55; 50%      = 61; 75% = 66.    Is there some way to create a bell curve chart and project what the 10th percentile, or 90th percentile, or any other percentile would be based on this limited information (using Excel) ?
LVL 17

Assisted Solution

jburgaard earned 500 total points
ID: 40563151
You can make a cumulated graph (X Y diagram) by means of the build-in statistical function inverse normal.
This is partly translated:  =norm.inv(P,mean,deviation)

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

LVL 17

Assisted Solution

jburgaard earned 500 total points
ID: 40563167
excel X Y graph from build in function
LVL 17

Accepted Solution

jburgaard earned 500 total points
ID: 40567950
If you want to SOLVE the percentile problem mentioned, you should use the mentioned build in (cumulated-)function.
If however you would like to ILLUSTRATE on a Bell-curve perhaps you should look into:
By the way, if this is a real-life-problem you could run into problem if the underlying distribution is not normal (that is if the 50%-percentil is not exact mid between 25% and 50%)


Author Closing Comment

ID: 40572630
Cool, thanks all !

Featured Post

Online Training Solution

Drastically shorten your training time with WalkMe's advanced online training solution that Guides your trainees to action. Forget about retraining and skyrocket knowledge retention rates.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This code takes an Excel list of URL’s and adds a header titled “URL List”. It then searches through all URL’s in column “A”, looking for duplicates. When a duplicate is found, it is moved to the top of the list. The duplicate URL’s are then highlig…
Some code to ensure data integrity when using macros within Excel. Also included code that helps secure your data within an Excel workbook.
The viewer will learn how to create a normally distributed random variable in Excel, use a normal distribution to simulate the return on an investment over a period of years, Create a Monte Carlo simulation using a normal random variable, and calcul…
This Micro Tutorial will demonstrate the scrolling table in Microsoft Excel using the INDEX function.

615 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question