Buzz
This article provides a comprehensive guide on using the CHITEST Function, which tests for independence.
Description: The function returns the probability value from the χ2 distribution for the given statistic. It is used to determine whether a hypothesis is to be accepted or rejected.
Syntax: CHITEST(actual_range,expected_range).
Herein:
- actual_range: The data range containing values to be compared with the expected value, is a mandatory parameter.
- expected_range: The data range containing the ratio of the product of the total rows and total columns with the grand total.
Note:
- The χ2 statistical test calculates χ2 using the formula:
Where:
+ Aij represents the actual frequency in the ith row, jth column.
+ Eij represents the expected frequency in the ith row, jth column.
+ r represents the number of rows.
+ c represents the number of columns.
- If actual_range and expected_range have different data points => the function returns the #N/A error value.
- The lower value only calculates independently, from the formula we observe χ2 is always positive and equals 0 only when Aij= Eij.
- CHITEST utilizes a distribution with degrees of freedom df. The calculation of df is as follows:
+ if r > 1 and c > 1 => df = (r-1)(c-1).
+ if r = 1 and c > 1 => df = (c-1).
+ if r > 1 and c = 1 => df = (r-1)
Since both r and c are not simultaneously equal to 1, there is no case where r = 1 and c = 1.
- Therefore, the CHITEST function is best applied when the values of Eij are not too small, Eij should be greater than or equal to 5 to achieve the most accurate results.
Example:
In the cell where calculation is needed input the formula: =CHITEST(D14:D16,D17:D19).
After entering the formula, press Enter to get the result:
Thus, the CHIPTEST value = 0.05300872 => Initially expected quite close to reality.
The above is the guide on how to use the CHIPTEST function, hoping to help you apply it more in your work.
Wishing you success!
