# Excel Normal Distribution

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• #49894

Dave Monroe
Participant

Just need a formula that will calculate the area under the standard normal curve for example..
A z score of 1.85 would give a .4678 result. I’ve tried normdist, normsdist ect. I’m missing something. any help would be appreciated.

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#171307

DaveS
Participant

Dave,
http://www.exceluser.com/explore/statsnormal.htm
Frst hit on a Google Excel standard normal
Well, at least you did try a little per my earlieer rant.

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#171308

Ropp
Participant

Tried all that.. actually been to that page I’m not sure what I’m doing wrong.

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#171310

DaveS
Participant

Dave,
Look at that article again.
The section on normsdist(z).Perhaps the confusion is that the function returns cumulative probability. A simple IF statement to subtract 0.5 from the answer if the z > 0 should fix that. You may have to do a nested IF to handle special case of 0. 0 should fix that. You may have to do a nested IF to handle special case of 0. 0 should fix that. You may have to do a nested IF to handle special case of 0.

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#171337

lin
Participant

If z = 1.85:
The area under the curve to the left of z = 1.85 is found using the following in Excel:
normsdist(1.85) = 0.968
You can also use: normdist(1.85, 0, 1, true) which is for the normal curve wiht average of 0 and standar devation of 1.
For the area under to the curve to the right of z = 1.85 simply use:
1-normsdist(1.85) = 0.032
I don’t know where you get your 0.4678 result.
Bill

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