Manuals/calci/CHIDIST

CHIDIST(x,df)

• $x$ is the value for which distribution is evaluated.
• $df$ is the number of degrees of freedom.

Description

• This function gives the one_tailed probability of the chi-squared distribution.
• It is denoted by $\chi ^{2}$ distribution.
• Normally categorical data's may displayed in tables. The $\chi ^{2}$ static used to compare the observed value in each table to the value which would be the expected under the assumption.
• The conditions of $\chi ^{2}$ test is

1. The table should be 2x2 or more than 2x2
2. Each observations should not be dependent
3. All expected values should be 10 or greater. 
4. The test statistic is:

$\chi ^{2}=\sum {\frac {(Oi-Ei)^{2}}{Ei}}$

The degrees of freedom are: (r–1)(c–1)

• r = No. of rows
• c = No. of columns

Where:

• Oi-the observed value in the ith cell
• Ei- the expected value in the ith cell

Also this function will the result as Error when

1. The x & df values are non-numeric
2. The x value is negative or df value is not an integer
3. The df <1 or df>10^10
4. Here CHIDIST=P(X>x),where X is a $\chi ^{2}$ random variable.

• CHIDIST(-2,1)=Error, because x is negative.
• CHIDIST(2,-1)=Error, because df<1

Examples

CHIDIST(x,df)	x	df	RESULT
CHIDIST(18,2)	18	2	0.0001234098
CHIDIST(15,1)	15	1	0.0001075112
CHIDIST(2,1)	2	1	0.157299207050
CHIDIST(-2,1)	(-2)	1	error
CHIDIST(2,-1)	2	(-1)	error

See Also

• CHITEST

References

CHI-SQUARE Distribution