Random sampling method, Applied Statistics

Random Sampling Method

In this method the units are selected in such a way that every item in the whole universe has an equal chance of being included. In the words of croxton  and Cowden. Sampling   is said to be random if each possible sample had the same probability of being drawn. Simpson Kafka said, A random sample is a sample is  a where each item in the universe has an equal or known opportunity of being selected.

Thu s if the size of sample is n from a finite universe of size N. The there are possible sample .A sampling technique in which each of the sample has an equal chance of being selected is known as random sample.

Method of Random Sampling: To ensure randomness of selection one may adopt either of the following methods;

(1)   Lottery Method: Under this method all items of the population are numbered on separate  slips of paper of identical size and shape .There slips are folded and mixed up in a drum .A blind fold selection is then made of the required number of sample size, the method is common in lottery draws where a decision for the prizes is to be made.

(2)   By Rotating Drum or Machine: In  this method a machine or a drum is used, In this machine  there are some discs on which  numbers from 0 to9 are graved, The number of discs will depend upon the units  of the population. If the total numbers in the universe is up to 999   three discs are required. If the number is from 1000 to9999 four discs will be needed. For every disc there is an index sing marked on it which identifies thedigit. all the discs are rotated and left. Wherever the discs are stopped the numbers are noted. In this manner desired units are selected.

(3)   By Random  Numbers :The random numbers are usually obtained by some mechanism which, when  repeated a large numbers  of items, ensures equal frequencies for the numbers from 0 to9 and also proper frequencies for various combinations  such as 00, 01,99,000,001,999, etc. That may be expected in a random sequence of digits 0 to 9.

Posted Date: 9/26/2012 7:22:26 AM | Location : United States







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

Write discussion on Random sampling method
Your posts are moderated
Related Questions
Discriminant analysis (DA) helps to determine which variables discriminate between two or more naturally occurring groups. Mathematically equivalent to MANOVA, it ' is extensively

how to get statistical quality control assignment in brief?

OmegaPlus Pty.Ltd. is a chain of Health Food stores operating in Australia: with 12 stores across Sydney, Melbourne and Brisbane. OmegaPlus has recently appointed a new CEO: San

For many decades, there has been considerable attention paid to identifying various factors that help to reduce the number of fatalities on Australian roads. In 1964 Victoria and S

What does the confidence level of a confidence interval tell you? Suppose that a population has mean, µ, and standard deviation, σ.  What does the central limit theorem tell us

Q. The following system of equations illustrates the algebraic form of a partial (individual) market equilibrium model, which is a model of price (P) and quantity (Q) determination

Regression line drawn as Y=C+1075x, when x was 2, and y was 239, given that y intercept was 11. calculate the residual

Coefficient of Variation The standard deviation discussed above is an absolute measure of dispersion. The corresponding relative measure is known as the coefficient of vari

#question what is the statistical process to reduce hardness of water

A researcher was interested lowering the high school dropout level in his county. He measured the reading level of students entering middle school (based on a standard test) and th