The formula for NORMSDIST is wrong?

S

SyBorg

nI tried using the equation from the help menu to verify NORMSDIST(1.3333),
as follows:

(EXP(-POWER(1.3333,2)/2))/SQRT(2*PI())

but I don't get the same answer. Instead, I get 0.164017.

What am I doing wrong?
 
B

Bernard Liengme

normSdist always returns the cumulative value (ie the area under the curve
up to value of z)
normdist lets you choose cumulative or not.
Also the first is set for mean = 0, stdev=1 while the second allows you to
specify these values.
The formula =NORMDIST(1.3333,0,1,0) returns 0.164017 since the last argument
of 0 specifies non-cumulative.
best wishes
 
D

David Biddulph

SyBorg said:
nI tried using the equation from the help menu to verify
NORMSDIST(1.3333),
as follows:

(EXP(-POWER(1.3333,2)/2))/SQRT(2*PI())

but I don't get the same answer. Instead, I get 0.164017.

What am I doing wrong?
Click to expand...

Doesn't the help say that NORMSDIST is the *cumulative* function, whereas
the (EXP(-POWER(z,2)/2))/SQRT(2*PI()) is the *density* function?
Plot each against z.
Integrate the density from z = - infinity and compare that with the
cumulative.
 
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