Normal Distribution f(x) Manual Calculation

[bs0d]

I'm trying to match the f(x) for a random variable based on what the function NORMDIST() is computing.

NORMDIST(x, mean, std dev, FALSE) for a Probability Density Function.


Assume mean = 229,352, & standard deviation = 204,444.

above function for variable: 2,836 returns: 0.0000011

When I try the manual calculation for the same number, i get: 0.0004776.

Heres the formula I'm using as provided in the help section for the NORMDIST function:

=(1/(SQRT(2*PI()*std_dev))*EXP(-((x-mean)^2/(2*std_dev^2))))

I must be interpreting the equation wrong?

 

[shg]

=1 / (SQRT(2*PI()) * sd) * EXP(-( (x - mean)^2 / (2*sd^2)) )

or

=1 / SQRT(2*PI()) / sd / EXP( (x-mean)^2 / (2*sd^2) )

 

[bs0d]

Thanks!