org.statcato.statistics.inferential

Class HypothesisTest1Var

java.lang.Object

org.statcato.statistics.inferential.HypothesisTest1Var

public class HypothesisTest1Var
extends java.lang.Object

A hypothesis test for 1 population variance

Since:

1.0

Constructor Summary

Constructors

Constructor and Description
HypothesisTest1Var(int n, double sigma2, double confidenceLevel, int testType) Constructor.

Method Summary

Modifier and Type	Method and Description
java.lang.String	criticalValue() Returns the critical value corresponding to the given confidence level and type of test.
double	pValue(double s2) Returns the p-value corresponding to s2 in a chi-square distribution.
double	testStatistics(double s2) Returns the test statistics for the given sample variance s2.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

HypothesisTest1Var

public HypothesisTest1Var(int n,
                          double sigma2,
                          double confidenceLevel,
                          int testType)

Constructor.

Parameters:

n - sample size

sigma2 - hypothesized variance

confidenceLevel - confidence level

testType - (as defined in HypothesisTest)

Method Detail

testStatistics

public double testStatistics(double s2)

Returns the test statistics for the given sample variance s2.

X2 = (n-1)^2 * s2 / sigma2

Parameters:

s2 - hypothesized population variance

Returns:

test statistic X2 (chi-square)

criticalValue

public java.lang.String criticalValue()

Returns the critical value corresponding to the given confidence level and type of test. Uses the chi-square distribution.

Returns:

critical value

See Also:

HypothesisTest

pValue

public double pValue(double s2)

Returns the p-value corresponding to s2 in a chi-square distribution.

Parameters:

s2 - variance

Returns:

p-value