Stratified sampling, Applied Statistics

Stratified Sampling

Stratified Sampling is generally used when the population is heterogeneous. In this case, the population is first subdivided into several parts (or small groups) called strata. According to some relevant characteristics so that each stratum is more or less homogeneous. Each stratum is called a sub-population. Then a small sample (called sub-sample) is selected from each stratum at random. All the sub-samples combined together form the Stratified Sample. This represents the population properly. The process of obtaining and examining a Stratified Sample with a view to estimate the characteristic of the population is known as Stratified Sampling.

Example 

The retailer can use Stratified Sampling as explained below:

She would analyze the bill copies according to items purchased, viz. TVs, Stereos, VCRs, etc. Each product’s customers would form a strata. Hence, we would have the following strata:

         TV buyers                                       

         Stereo buyers                                 

         VCR buyers                    

For each stratum, random sampling would be done. 

Posted Date: 9/15/2012 3:00:52 AM | Location : United States







Related Discussions:- Stratified sampling, Assignment Help, Ask Question on Stratified sampling, Get Answer, Expert's Help, Stratified sampling Discussions

Write discussion on Stratified sampling
Your posts are moderated
Related Questions
Large Sample Test for Proportion A random sample of size n (n > 30) has a sample proportion p of members possessing a certain attribute (success). To test the hypothesis that t

Each weekend, Derek either reads a book (B), goes to the cinema (C), visits his local museum (M), or plays squash (S). If he reads a book one weekend, then he will take part in one

Why are graphs and tables useful when examining data? A researcher is comparing two middle school 7th grade classes. One class at one school has participated in an arts program

A study was conducted to determine the amount of heat loss for a certain brand of thermal pane window. Three different windows were randomly subjected to each of three different ou

Quota sampling Under this method enumerators shall select the respondents in place of those not available, as per the quota fixed according  to guide lines   provided to them.

i need to solve couple questions on a data set ?

Variance The term variance was used to describe the square of the standard deviation by R.A.Fisher. The concept of variance is highly important in areas where it is possible to

how do i determine the 40th percentile in an ogive graph

Accelerated Failure Time Model A basic model for the data comprising of survival times, in which the explanatory variables measured on an individual are supposed to act multipli

Ask 3. Precision Manufacturing has a government contract to produce stainless steel rods for use in military aircraft. Each rod is required to be 20 millimeters in diameter. Each