Difference between revisions of "Manuals/calci/STDEV"

Revision as of 15:06, 27 July 2017

STDEV(n1,n2,n3…)

This function gives the Standard Deviation based on a given sample.
Standard Deviation is the quantity expressed by, how many members of a group differ from the mean value of the group.
It is the used as a measure of the dispersion or variation in a distribution.
It is calculated as the square root of variance.
In $STDEV(n1,n2,n3...)$ , $n1,n2,n3...$ , are numbers to find the Standard Deviation.
Here $n1$ is required. $n2,n3,...$ are optional.
Instead of numbers, we can use the single array or a reference of a array.
$STDEV$ is defined by the formula:

 $S.D={\sqrt {\frac {\sum (x-{\bar {x}})^{2}}{(n-1)}}}$

where ${\bar {x}}$ is the sample mean of $x$ and $n$ is the total numbers of the given data.

It is calculated using $n-1$ method.
This function is considering our given data is the sample of the population.
Suppose it should consider the data as the entire population, we can use the STDEVP function.
The arguments can be be either numbers or names, array,constants or references that contain numbers.
Suppose the array contains text,logical values or empty cells, like that values are not considered.
When we are entering logical values and text representations of numbers as directly, then the arguments are counted.
Suppose the function have to consider the logical values and text representations of numbers in a reference , we can use the STDEVA function.
This function will return the result as error when

     1. Any one of the argument is non-numeric. 
     2. The arguments containing the error values or text that cannot be translated in to numbers.

=STDEV(18,25,76,91,107) = 39.8660256358
=STDEV(208,428,511,634,116,589,907) = 267.0566196431
=STDEV(A1:F1) = 5.52871293039
=STDEV(A2:D2) = 3.304037933599
=STDEV(A3:B3) = 1.414213562373
=STDEV(12,18,27,32,FALSE) = 12.617448236470002

@@ Line 13: / Line 13: @@
   <math>S.D= \sqrt \frac {\sum(x-\bar{x})^2}{(n-1)} </math>
 where <math> \bar{x} </math> is the sample mean of <math> x </math> and <math> n </math> is the total numbers of the given data.
-*It is calculated using <math>"n-1"</math> method.
+*It is calculated using <math>n-1</math> method.
 *This function is considering our given data is the sample of the population.
 *Suppose it should consider the data as the entire population, we can use the [[Manuals/calci/STDEVP  | STDEVP ]] function.