Excel Function NORMDIST

NORMDIST(x, mean, standard_dev, cumulative)

Returns the probability of getting less than or equal to a particular value in a normal distribution.

x	The number from the distribution.
mean	The arithmetic mean of the distribution.
standard_dev	The standard deviation of the distribution.
cumulative	The type of function to use: True = cumulative probability function (less than) False = probability density function (equal to)

Remarks

* NORM.DIST was added in Excel 2010 to replace this function.
* The normal distribution is a continuous distribution.
* If "x" is not numeric, then #VALUE! is returned.
* If "mean" is not numeric, then #VALUE! is returned.
* If "standard_dev" = 0, then #NUM! is returned.
* If "standard_dev" is not numeric, then #VALUE! is returned.
* If "cumulative" = True, then the area under the curve to the left of "x" is returned. This uses the cumulative distribution function.
* If "cumulative" = False, then the height of the curve at "x" is returned. This uses the probability density function.
* Example - If "mean" = 0 and "standard_dev" = 1 this function is equivalent to the standard normal distribution.
* In Excel 2010 the accuracy of this function was improved - https://support.microsoft.com/en-us/help/827371/description-of-the-normdist-function-in-excel
* For the Microsoft documentation refer to support.office.com

	A
1	=NORMDIST(0,0,1,TRUE) = 0.5
2	=NORMDIST(-1,0,1,TRUE) = 0.159
3	=NORMDIST(1,0,1,TRUE) = 0.841
4	=NORMDIST(0,0,1,FALSE) = 0.399
5	=NORMDIST(1,0,1,FALSE) = 0.242
6	=NORMDIST(42,40,1.5,TRUE) = 0.909
7	=NORMDIST(42,40,10,TRUE) = 0.579
8	=NORMDIST(42,40,1.5,) = 0.109
9	=NORMDIST("42",40,1.5,) = 0.109
10	=NORMDIST(42,40,,) = #NUM!
11	=NORMDIST(42,"some text",1.5,) = #VALUE!