Manuals/calci/CHITEST

Revision as of 01:41, 25 November 2013 by Abin (talk | contribs) (→‎Description)
CHITEST(ar,er)


  • is the array of observed values
  • is the array of expected values

Description

  • This function gives the the value from the chi-squared distribution. i.e it calculates   statistic and degrees of freedom, then calls CHIDIST.

The conditions of   test is

The table should be 2x2 or more than 2x2
Each observations should not be dependent
All expected values should be 10 or greater. 
Each cell has an expected frequency of at least five.
  • The   test first calculates a   statistic using the formula:

 

  •   is the array of the observed values in a given set of values
  •  
  • observed and expected must have the same number of rows and columns and there must be atleast 2 values in each.
  • A low result of   is an indicator of independence.
  • From the formula of   we will get   is always positive or 0.
  • 0 only if observed ij=expected ij for each i and j.
  • CHITEST uses the   distribution with the number of Degrees of Freedom df.
where df=(r-1)(c-1),r>1 and c>1.
If r=1 and c>1, then df = c-1 or if r>1 and c=1, then df=r-1.
If r=c=1 then this function will give the error result


Column1 Column2 Column3 Column4
Row1 45 38 0.000313
Row2 10 23
Row3 12 26
Row4 40.5 49.36
Row5 19.56 16.44
Row6 17.05 17.41
Let’s see an example
B C
45 38
10 23
12 26
40.5 49.36
19.56 16.44
17.05 17.41
CHITEST (a, b)
i.e. =CHITEST (B2; C4, B5:C7) is 0.003