Manuals/calci/CHIDIST

CHIDIST (Number,DegreeOfFreedom)

• $Number$ is the value for which distribution is evaluated.
• $Degreeoffreedom$ is the number of degrees of freedom.
  • CHIDIST(), returns the one-tailed probability of the chi-squared distribution.

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 assumed value.
• 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.

• The test statistic is:

$\chi ^{2}=\sum {\frac {(Oi-Ei)^{2}}{Ei}}$ The degrees of freedom is: (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 $Number$ & $Degreeoffreedom$ values are non-numeric
2. The $Number$ value is negative or $Degreeoffreedom$ value is not an integer
3. The $Degreeoffreedom<1$ or $Degreeoffreedom>10^{10}$
4. Here CHIDIST=P(X>x),where X is a $\chi ^{2}$ random variable.

• CHIDIST(-2,1)=Error, because Number is negative.
• CHIDIST(2,-1)=Error, because Degreeoffreedom<1

ZOS

• The syntax is to calculate CHIDIST in ZOS is CHIDIST(Number,Degreeoffreedom).
• $Number$ is the value for which distribution is evaluated.
• $Degreeoffreedom$ is the number of degrees of freedom.
• For e.g.,CHIDIST(10..12,5.1..7.1..0.6)

Chi-squared Distribution

Examples

CHIDIST(Number,Degreeoffreedom)	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	#N/A (NUMBER > 0)
CHIDIST(2,-1)	2	-1	null

Related Videos

Chi-Square Distribution

See Also

• CHITEST

References

CHI-SQUARE Distribution

• List of Main Z Functions

• Z3 home