org.statcato.statistics.inferential
Class HypothesisTest2MeanSigmaUnknown

java.lang.Object
  extended by org.statcato.statistics.inferential.HypothesisTest2MeanSigmaUnknown

public class HypothesisTest2MeanSigmaUnknown
extends java.lang.Object

A hypothesis test for 2 population means (population standard deviations sigmas unknown).

Since:
1.0
Version:
%I%, %G%
Author:
Margaret Yau

Constructor Summary
HypothesisTest2MeanSigmaUnknown(int n1, int n2, double xBar1, double xBar2, double s1, double s2, double diff, double confidenceLevel, int testType, boolean varEqual)
          Constructor.
 
Method Summary
 java.lang.String criticalValue()
          Returns the critical value corresponding to the given confidence level and type of test.
 int DOF()
          Returns the degree of freedom.
 double pValue()
          Returns the p-value.
 double testStatistics()
          Returns the test statistics.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

HypothesisTest2MeanSigmaUnknown

public HypothesisTest2MeanSigmaUnknown(int n1,
                                       int n2,
                                       double xBar1,
                                       double xBar2,
                                       double s1,
                                       double s2,
                                       double diff,
                                       double confidenceLevel,
                                       int testType,
                                       boolean varEqual)
Constructor.

Parameters:
n1 - sample size 1
n2 - sample size 2
xBar1 - sample mean 1
xBar2 - sample mean 2
s1 - sample standard deviation 1
s2 - sample standard deviation 2
diff - hypothesized difference in population mean
confidenceLevel - confidence level
testType - type of test (as defined in HypothesisTest)
varEqual - whether population variances are assumed equal
Method Detail

testStatistics

public double testStatistics()
Returns the test statistics.

Returns:
test statistic t score

DOF

public int DOF()
Returns the degree of freedom.

Returns:
degree of freedom

criticalValue

public java.lang.String criticalValue()
Returns the critical value corresponding to the given confidence level and type of test. Uses the Student's t distribution.

Returns:
critical value
See Also:
HypothesisTest

pValue

public double pValue()
Returns the p-value.

Returns:
p-value