Excel Function NORMINV

NORMINV(probability, mean, standard_dev)

Returns the x variable corresponding to less than a particular probability.

probability	The probability associated with the distribution.
mean	The arithmetic mean of the distribution.
standard_dev	The standard deviation of the distribution.

Remarks

* NORM.INV was added in Excel 2010 to replace this function.
* The normal distribution is a continuous distribution.
* If "probability" < 0, then #NUM! is returned.
* If "probability" > 1, then #NUM! is returned.
* If "probability" 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.
* This function uses an iterative technique for calculating the function.
* Given a "probability" value, this function iterates until the result is accurate to within ±3x10^-7.
* If this function does not converge after 100 iterations, then #N/A is returned.
* In Excel 2010 the accuracy of this function was improved.
* For the Microsoft documentation refer to support.office.com

	A
1	=NORMINV(99%,0,1) = 2.326
2	=NORMINV(50%,0,1) = 0.0
3	=NORMINV(25%,0,1) = -0.674
4	=NORMINV(5%,0,1) = -1.645
5	=NORMINV(0.908789,40,1.5) = 42
6	=NORMINV(0.87,0,1) = 1.126
7	=NORMINV(NORMDIST(0.87,0,1,TRUE),0,1) = 0.87
8	=NORMINV(100%,0,1) = #NUM!
9	=NORMINV(1,0,1) = #NUM!
10	=NORMINV(-1,40,1.5) = #NUM!
11	=NORMINV(2,40,1.5) = #NUM!
12	=NORMINV(0.908789,"some text",1.5) = #VALUE!