Formulas and Functions

Chapter 10 Statistical Functions 293
“Using the Keyboard and Mouse to Create and Edit Formulas” on page 26
“Pasting from Examples in Help” on page 41
STDEVP
The STDEVP function returns the standard deviation, a measure of dispersion, of a
collection of values based on their population (true) variance.
STDEVP(num-date-dur, num-date-dur…)
 num-date-dur: A value. num-date-dur is a number value, a date/time value, or a
duration value.
 num-date-dur…:Optionally include one or more additional values. If more than
one num-date-dur value is specied, all must be of the same type.
Usage Notes
It is appropriate to use STDEVP when the specied values represent the entire Â
collection or population. If the values you are analyzing represent only a sample of a
larger population, use the STDEV function.
If you want to include text or Boolean values in the computation, use the STDEVPA Â
function.
The standard deviation is the square root of the variance returned by the VARP Â
function.
Example
Assume you have administered ve tests to a group of students. You have a very small class and
this represents the total population of your students. Using this population data, you could use the
STDEVP function to determine which test had the widest dispersion of test scores.
The results of the STDEVP functions are approximately 20.3961, 21.9454, 8.49994, 7.2222, and 2.9933.
So test 2 had the highest dispersion, followed closely by test 1. The other three tests had low
dispersion.
Test 1 Test 2 Test 3 Test 4 Test 5
Student 1 75 82 90 78 84
Student 2 100 90 95 88 90
Student 3 40 80 78 90 85
Student 4 80 35 95 98 92
Student 5 75 82 90 78 84
=STDEVP(B2:B6) =STDEVP(C2:C6) =STDEVP(D2:D6) =STDEVP(E2:E6) =STDEVP(F2:F6)