Purpose
Return value
Syntax
=STDEVPA(number1,[number2],...)
- number1 - First number or reference in the sample.
- number2 - [optional] Second number or reference.
Using the STDEVPA function
The STDEVPA function calculates the standard deviation for data that represents an entire population, evaluating text and logicals as numbers as part of the calculation. TEXT is evaluated as zero, TRUE is evaluated as 1, and FALSE is evaluated as zero.
Standard deviation is a measure of how much variance there is in a set of numbers compared to the average (mean) of the numbers. The STDEVPA function is meant to estimate standard deviation for an entire population. If data represents a sample, use the STDEVA function.
In the example shown, the formula in E5 is:
=STDEVPA(B5:B11)
Standard Deviation functions in Excel
The table below summarizes the standard deviation functions provided by Excel.
| Name | Data set | Text and logicals |
|---|---|---|
| STDEV | Sample | Ignored |
| STDEVP | Population | Ignored |
| STDEV.S | Sample | Ignored |
| STDEV.P | Population | Ignored |
| STDEVA | Sample | Evaluated |
| STDEVPA | Population | Evaluated |
Notes:
- Only use STDEVPA when you need to evaluate logicals or text in the standard deviation calculation.
- STDEVPA calculates standard deviation using the “n” method.
- STDEVA assumes data is an entire population. When data representations a sample, use STDEVA or STDEV.S
- Numbers are supplied as arguments. They can be supplied as actual numbers, ranges, arrays, or references that contain numbers.
- STDEVPA will evaluate logical values and/or numbers in supplied references. To ignore these values use STDEVP or STDEV.P
Purpose
Return value
Syntax
=TRIMMEAN(array,percent)
- array - Values to trim and average.
- percent - The number of data points to exclude from the calculation.
Using the TRIMMEAN function
The Excel TRIMMEAN function calculates mean (average) while excluding outliers. The number of data points to exclude is provided as a percentage.
TRIMMEAN works by first excluding values from the top and bottom of a data set, then calculating mean. The number of data points is provided as a percentage. The percentage can be input either in decimal format or percent format:
=TRIMMEAN(A1:A100,0.1) // exclude 10%
=TRIMMEAN(A1:A100,10%) // exclude 10%
=TRIMMEAN(A1:A100,0.2) // exclude 20%
=TRIMMEAN(A1:A100,20%) // exclude 20%
It’s important to note that TRIMMEAN rounds excluded data points down to the nearest multiple of 2. For example, with 50 data points, 10% equals 5 values. In this case, TRIMMEAN will round 5 down to 4, then exclude two values from the top, of the data set, and two values from the bottom of the data set.
