Stdevp
The Population Standard Deviation of the selection.
The Stdevp deals with the complete population where as Stdev deals with a population sample only.
The formula:
Sample 1:
Population: A set of data that is all inclusive.
Populations are often very large. For simplicity, imagine the following as an example:
12, 6, 12
Computing the Stdevp

Determine the mean of the sample.
12+6+12/3=10

Square the difference between each item and the mean
(1210)^2 =4
(610)^2 =16
(1210)^2 =4

Calculate the average.
4+16+4/3=24/3

Calculate the square root
Sample 2:
Given the following sample fields:
Number 
Arbitrary 
Negative Values 
Positive Values 
One 
Binary 
Currency 
Decimal 
1 
3 
1 
1 
1 
0 
$1.00 
1.01 
2 
2 
2 
2 

1 
$10.00 
2.02 
3 
3 
3 
3 

0 
$100.00 
3.03 
4 
0 
4 
4 

1 
$1,000.00 
4.04 
5 
1 
5 
5 

0 
$10,000.00 
5.05 
6 
2 
6 
6 

1 
$1.00 
6.06 
7 
3 
7 
7 

0 
$10.00 
7.07 
8 
0 
8 
8 


$100.00 
8.08 
9 
0 
9 
9 


$1,000.00 
9.09 
10 
0 
10 
0 


$0.00 
0.00 
Sample fields
The Stdevp for each field:
Number 
Arbitrary 
Negative Values 
Positive Values 
One 
Binary 
Currency 
Decimal 
2.8723 
16733 
2.8723 
2.8723 
0 
.4949 
$3,033.4832 
2.9010 
Results per field