Difference between revisions of "Manuals/calci/TTESTEQUALVARIANCES"

Revision as of 00:16, 4 February 2014

TTESTTWOSAMPLESEQUALVARIANCES(ar1,ar2,md,alpha,lv)

This function calculating the two Sample for equal variances determines whether two sample means are equal.
We can use this test when both:
1.The two sample sizes are equal;
2.It can be assumed that the two distributions have the same variance.
In $TTESTTWOSAMPLESEQUALVARIANCES(ar1,ar2,md,alpha,lv)$ , $ar1$ and $ar2$ are two arrays of sample values. $md$ is the Hypothesized Mean Difference .
Suppose md=0 which indicates that sample means are hypothesized to be equal.
$alpha$ is the significance level which ranges from 0 to 1.
$lv$ is the logical value like TRUE or FALSE.
TRUE is indicating the result will display in new worksheet.Suppose we are omitted the lv value it will consider the value as FALSE.
The t statistic of this function calculated by:

 $t={\frac {{\bar {x_{1}}}-{\bar {x_{2}}}}{s_{x1}.s_{x2}.{\sqrt {\frac {2}{n}}}}}$

where $s_{x1}.s_{x2}={\sqrt {{\frac {1}{2}}(s_{x1}^{2}+s_{x2}^{2})}}$

Here $s_{x1}$ and $s_{x2}$ are unbiased estimators of the variances of two samples. $s_{x1}.s_{x2}$ is the grand standard deviation data 1 and data2 and n is the data points of two data set.
This function will give the result as error when

  1.any one of the argument is non-numeric.
  2.alpha>1
  3. $ar1$  and  $ar2$  are having different number of data points.

Spreadsheet
	A	B	C	D	E	F
1	10	15	18	27	12	34
2	17	20	25	39	9	14

@@ Line 19: / Line 19: @@
   <math>t = \frac{\bar{x_1}-\bar{x_2}}{s_{x1}.s_{x2}.\sqrt{\frac{2}{n}}}</math>
 where <math>s_{x1}.s_{x2} = \sqrt{\frac{1}{2}(s_{x1}^2+s_{x2}^2)}</math>
-*Here <math>s_x_1</math> and <math>s_x_2</math> are unbiased estimators of the variances of two samples.<math>s_{x1}.s_{x2}</math> is the grand standard deviation data 1 and data2 and n is the data points of two data set.
+*Here <math>s_{x1}</math> and <math>s_{x2}</math> are unbiased estimators of the variances of two samples.<math>s_{x1}.s_{x2}</math> is the grand standard deviation data 1 and data2 and n is the data points of two data set.
 *This function will give the result as error when
 .any one of the argument is non-numeric.