Stratified sampling examples

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From this stratified population, we wish to take a sample of <math>n=10</math>, taking <math>n_1=4</math> from the first stratum and <math>n_2=n_3=3</math> from the other two strata. The stratum parametric means and variances are given in Table 1.                 
 
From this stratified population, we wish to take a sample of <math>n=10</math>, taking <math>n_1=4</math> from the first stratum and <math>n_2=n_3=3</math> from the other two strata. The stratum parametric means and variances are given in Table 1.                 
  
====Table 1====
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Table 1: Stratum parameters for the stratified example population.
Stratum parameters for the stratified example population.
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Revision as of 18:30, 16 December 2010

Example 1

Illustration why stratification is most efficient when the strata meansare as different as possible

Imagine the example population of \(N=30\) elements be subdivided into three strata as in the figure on the right. Here, stratification has been done arbitrarily into three strata of size 14, 8 and 8.

From this stratified population, we wish to take a sample of \(n=10\), taking \(n_1=4\) from the first stratum and \(n_2=n_3=3\) from the other two strata. The stratum parametric means and variances are given in Table 1.

Table 1: Stratum parameters for the stratified example population.

Stratum \(N_h\,\) \(n_h\,\) \(\mu_h\,\) \(\sigma_h^2\,\)
1 14 4 6.29 3.49
2 8 3 10.13 4.86
3 8 3 5.38 2.48
Construction.png sorry: 

This section is still under construction! This article was last modified on 12/16/2010. If you have comments please use the Discussion page or contribute to the article!

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