org.statcato.statistics.inferential

Class SampleSizeDetermination

java.lang.Object

org.statcato.statistics.inferential.SampleSizeDetermination

public class SampleSizeDetermination
extends java.lang.Object

Functions for determining the sample size estimating a population statistic.

Since:

1.0

Constructor Summary

Constructors

Constructor and Description
SampleSizeDetermination()

Method Summary

Modifier and Type	Method and Description
static int	mean(double alpha, double stdev, double error) Returns the sample size for estimating a population mean given the significance level, standard deviation, and margin of error.
static int	proportion(double alpha, double estimate, double error) Returns the sample size for estimating a population proportion given the significance level, proportion estimate, and margin of error.

Methods inherited from class java.lang.Object

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

Constructor Detail

SampleSizeDetermination

public SampleSizeDetermination()

Method Detail

proportion

public static int proportion(double alpha,
                             double estimate,
                             double error)

Returns the sample size for estimating a population proportion given the significance level, proportion estimate, and margin of error. n = z^2 * p * q / E^2 if proportion estimate p is known (z is the critical value based on the significance level, E is the margin of error, and q is 1 - p.) n = z^2 * 0.25 / E^2 if proportion estimate is unknown

Parameters:

alpha - significance level

estimate - proportiion estimate (-1 if unknown)

error - margin of error

Returns:

sample size

mean

public static int mean(double alpha,
                       double stdev,
                       double error)

Returns the sample size for estimating a population mean given the significance level, standard deviation, and margin of error. n = [z * sigma / E]^2 where z is the critical value given the significance level, sigma is the population standard deviation, and E is the margin of error.

Parameters:

alpha - significance level

stdev - population standard deviation

error - margin of error

Returns:

sample size