STDEVA
The STDEVA function returns the standard deviation — a measure of dispersion — of a set containing any values, based on the sample (unbiased) variance.
STDEVA(value, value…)
value: A single value or a collection. All values must be of the same value type (except that string values and boolean values can be included with number values). A minimum of two values are required. A string value can be included in a referenced cell, but can’t be directly entered as an argument to the function.
value…: Optionally include one or more additional values or collections.
Notes
It is appropriate to use STDEVA when the specified values represent only a sample of a larger population. If the values you are analysing represent the entire collection or population, use the STDEVPA function.
The function assigns a value of 0 to any string value, 0 to the boolean value FALSE, and 1 to the boolean value TRUE and includes them in the computation, if all other values are numbers. If there are date/time values or duration values included, the function returns an error. Empty cells are ignored.
The standard deviation is the square root of the variance returned by the VARA function.
Example |
|---|
Suppose you installed a temperature sensor in a house in California. The sensor records each day’s high and low temperatures in degrees Fahrenheit. The data from the first few days of July is shown in the following table and is used as a sample for the population of high and low temperatures (note that this is an example only; this would not be statistically valid). On July 5, the sensor failed, so the data in the table shows n/a, or not available. |
A | B | C | |
|---|---|---|---|
1 | Date | High | Low |
2 | 7/1/10 | 58 | 58 |
3 | 7/2/10 | 84 | 61 |
4 | 7/3/10 | 82 | 59 |
5 | 7/4/10 | 78 | 55 |
6 | 7/5/10 | n/a | n/a |
7 | 7/6/10 | 81 | 57 |
8 | 7/7/10 | 93 | 67 |
=STDEVA(B2:B8) returns approximately 31.8067078879073, the dispersion (standard deviation is a measure of dispersion) as measured by STDEVA, of the sample of daily high temperatures. If you had a large data set that could not easily be visually scanned, or you wished to automate checking for missing values, you could compare the results of =STDEV(B2:B8), which returns approximately 11.6218185610801, and STDEVA, which returns approximately 31.8067078879073. If (as in this case) they are not equal, it would indicate the data set contains text (such as “n/a”), or one or more boolean values (TRUE or FALSE). |