Difference between revisions of "Manuals/calci/FTESTANALYSIS"

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<div style="font-size:30px">'''FTEST(ar1,ar2)'''</div><br/>
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<div style="font-size:30px">'''FTESTANALYSIS(ar1,ar2,alpha,newtableflag)'''</div><br/>
 
*<math>ar1</math> and <math>ar2 </math> are array of data.
 
*<math>ar1</math> and <math>ar2 </math> are array of data.
 +
*<math>alpha</math>  is the significance level.
 +
*<math>newtableflag</math>  is the logical value.
 +
 
==Description==
 
==Description==
*This function gives the result of F-test.  
+
*This function gives the analysis of variance.
*The F-test is designed to test if two population variances are equal.  
+
*This statistics used to determine the significant difference of three or more variables or multivariate collected from experimental
*It does this by comparing the ratio of two variances.  
+
research.
*So, if the variances are equal, the ratio of the variances will be 1.
+
*So this analysis is depending on the hypothesis.
*Let X1,...Xn and Y1...Ym be independent samples each have a Normal Distribution .
+
*The hypotheses for this test are
*It's sample means:
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<math>H_0: \sigma_1 = \sigma_2 </math>  (null hypothesis, variances are equal)
<math>\bar X=\frac{1}{n} \sum_{i=1}^n Xi</math>
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<math>H_0: \sigma_1 \ne \sigma_2 </math>  (alternative hypothesis, variances are not equal)
and  
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*For example, the comparison of SCORES across GROUPS,where there are two groups.
:<math>\bar Y =\frac {1}{m} \sum_{i=1}^m Yi</math> .  
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*The purpose is to determine if the mean SCORE on a test is different for the two groups tested (i.e., control and treatment groups)
*The sample variances :
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*In FTESTANALYSIS(ar1,ar2,alpha,newtableflag) where <math>ar1</math> is the data of first array, <math>ar2</math> is the data of second array.
<math>SX^2=\frac{1}{n-1} \sum_{i=1}^n (Xi-\bar X)^2</math>
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*<math> alpha </math> is the significance level which ranges from 0 to 1.
and
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*<math> newtableflag </math> is the logical value like TRUE or FALSE.
:<math>SY^2=\frac{1}{m-1} \sum_{i=1}^m (Yi-\bar Y)^2</math>
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*TRUE is indicating the result will display in new worksheet.Suppose we are omitted the lv value it will consider the value as FALSE.
*Then the Test Statistic = <math>\frac {Sx^2}{Sy^2}</math> has an F-distribution with <math>n−1</math> and <math>m−1</math> degrees of freedom.
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*The F statistic of this function calculated by:
*In FTEST(ar1,ar2) where <math>ar1</math> is the data of first array, <math>ar2</math> is the data of second array.  
+
<math>\frac {Sx^2}{Sy^2}</math> has an F-distribution with <math>n−1</math> and <math>m−1</math> degrees of freedom.
*The array may be any numbers, names, or references that contains numbers.  
+
*Also <math>Sx^2 </math> is the sample variance of first set of values.
 +
*And <math>Sy^2 </math> is the sample variance of first set of values.
 +
*If the f-value from the test is higher than the f-critical value then the null hypothesis should be rejected and the variances are unequal.
 +
*So the following cases will occur:
 +
*If the variances are assumed to NOT be equal, proceed with the t-test that assumes non-equal variances.
 +
*If the variances are assumed to be equal, proceed with the t-test that assumes equal variances.
 +
*In this function the array may be any numbers, names, or references that contains numbers.  
 
*values are not considered if the array contains any text, logical values or empty cells.  
 
*values are not considered if the array contains any text, logical values or empty cells.  
 
When the <math>ar1</math> or <math>ar2</math> is less than 2 or the variance of the array value is zero, then this function will return the result as error.
 
When the <math>ar1</math> or <math>ar2</math> is less than 2 or the variance of the array value is zero, then this function will return the result as error.

Revision as of 14:27, 2 June 2015

FTESTANALYSIS(ar1,ar2,alpha,newtableflag)


  • and are array of data.
  • is the significance level.
  • is the logical value.

Description

  • This function gives the analysis of variance.
  • This statistics used to determine the significant difference of three or more variables or multivariate collected from experimental

research.

  • So this analysis is depending on the hypothesis.
  • The hypotheses for this test are
  (null hypothesis, variances are equal)
  (alternative hypothesis, variances are not equal)
  • For example, the comparison of SCORES across GROUPS,where there are two groups.
  • The purpose is to determine if the mean SCORE on a test is different for the two groups tested (i.e., control and treatment groups)
  • In FTESTANALYSIS(ar1,ar2,alpha,newtableflag) where is the data of first array, is the data of second array.
  • is the significance level which ranges from 0 to 1.
  • 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 F statistic of this function calculated by:

has an F-distribution with Failed to parse (syntax error): {\displaystyle n−1} and Failed to parse (syntax error): {\displaystyle m−1} degrees of freedom.

  • Also is the sample variance of first set of values.
  • And is the sample variance of first set of values.
  • If the f-value from the test is higher than the f-critical value then the null hypothesis should be rejected and the variances are unequal.
  • So the following cases will occur:
  • If the variances are assumed to NOT be equal, proceed with the t-test that assumes non-equal variances.
  • If the variances are assumed to be equal, proceed with the t-test that assumes equal variances.
  • In this function the array may be any numbers, names, or references that contains numbers.
  • values are not considered if the array contains any text, logical values or empty cells.

When the or is less than 2 or the variance of the array value is zero, then this function will return the result as error.

Examples

1.

DATA1
15 27 19 32
DATA2
21 12 30 11
=FTEST(B4:B8,C4:C8)=0.81524906747183

2.

DATA1
5 8 12 45 23
DATA2
10 20 30 40 50
=FTEST(A1:A5,C1:C5)=0.9583035732212274  

3.

DATA1
14 26 37
DATA2
45 82 21 17
FTEST(B1:B3,C1:C4} = 0.26412211240525474

4.

DATA1
14
DATA1
45 65
=FTEST(B1,C2:C3)=NAN

See Also

References

F Test