org.statcato.statistics.inferential
Class CIOnePopMeanSigmaKnown

java.lang.Object
  org.statcato.statistics.inferential.ConfidenceInterval
      org.statcato.statistics.inferential.CIOnePopMeanSigmaKnown

public class CIOnePopMeanSigmaKnown
extends ConfidenceInterval

Confidence interval class for one population mean, sigma (population standard deviation) known.

Since:

1.0

Version:

%I%, %G%

Author:

Margaret Yau

Field Summary

Fields inherited from class org.statcato.statistics.inferential.ConfidenceInterval

center, confidenceLevel

Constructor Summary

CIOnePopMeanSigmaKnown(double confidenceLevel, int n, double mean, double sigma)
Constructor.

Method Summary

double	criticalValue() Returns the critical value corresponding to the given confidence level.
double	marginOfError() Returns the margin of error.

Methods inherited from class org.statcato.statistics.inferential.ConfidenceInterval

lowerLimit, toString, upperLimit

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

CIOnePopMeanSigmaKnown

public CIOnePopMeanSigmaKnown(double confidenceLevel,
                              int n,
                              double mean,
                              double sigma)

Constructor.

Parameters:

confidenceLevel - confidence level, between 0 and 1

n - sample size

mean - sample mean

sigma - sample standard deviation

Method Detail

marginOfError

public double marginOfError()

Returns the margin of error. E = z_(alpha/2) * sigma / sqrt(n).

Specified by:

marginOfError in class ConfidenceInterval

Returns:

margin of error

criticalValue

public double criticalValue()

Returns the critical value corresponding to the given confidence level. Uses the z distribution to find z_(alpha/2), where alpha is the significance level (1 - confidence level).

Specified by:

criticalValue in class ConfidenceInterval

Returns:

critical value