Normal distribution shaped graph

Hi,

It sounds like you need to get advice initially from perhaps a Maths Forum somewhere.

Once you've got your statistical data then perhaps you could come back to this site with a sample and we could help you to create the Chart from your data.

Regards

I think you can do this by using the =NORMDIST() function http://office.microsoft.com/en-us/ma...457.aspx?CTT=1 Note that this function is being replaced with the NORM.DIST function, I'm just not sure which version the newer function applies to. From a table of x,=NORMDIST(x,mean,stddev,FALSE) you should be able to generate the desired curve.

Also, to get the range for 2 SD, do I go:
mean - SD X SD and
mean + SD X SD?

That looks more like mean +/- sd^2. I think what you want is mean+(sd+sd) and mean-(sd+sd)

1) Put the mean and sd in their own cells (maybe A2 and B2)
2) In column A (maybe start in row 5) put a series of x values covering the desired range (maybe mean +/- 5 * sd so 55 to 110 step 2 or something).
3) In column B adjacent to the x values, put an appropriate variation of the aforementioned =NORMDIST() function. =NORMDIST(A5,$A$2,$B$2,false) copied down.
4) Plot column B against colum A in a scatter plot.

Some explanations can be found ...

http://tushar-mehta.com/excel/charts..._distribution/

http://www.exceluser.com/explore/nor...-new-excel.htm

http://www.vertex42.com/ExcelArticle...ion-Excel.html

B5 comes up with 2.97344E-07

Is this not the correct answer? This is what I get and it seems correct. Are you expecting a different answer?

As noted in the other thread, you need to learn how to use absolute references to fix a reference when you copy it. http://office.microsoft.com/en-us/ex...940.aspx?CTT=1

Yes, that looks right. As for what the graph means, it would be difficult to explain it in any detail. Discussion of what a normal distribution is and what it means occupies a significant portion of an intro to stats course, and I'm not sure it is fair to ask someone on a random internet forum to try to recreate that much information. IIRC, my stats text uses histograms to introduce normal distributions, then builds on the concept from there.

This seems to be a good, brief article http://statistics.about.com/od/Helpa...Bell-Curve.htm

the Wikipedia article http://en.wikipedia.org/wiki/Normal_distribution is probably too detailed of a discussion, but it does have a nice graph showing four different normal distributions, so you can see how the mean and standard deviation change what it looks like.

If you can get a hold of a good intro to stats text, I would probably suggest you start in the index, find the first reference to a normal distribution, and see what it says. You may need to go further back if there are concepts you don't understand. I would also suggest internet searches for "introduction to normal distributions" or similar to find tutorials that I'm sure are available on the internet.