Sampling, Applied Statistics

Assignment Help:

Sampling

Population is a collection of all the data points being studied. For example, if we are studying the annual incomes of all the people in India, then the population under study would consist of data points representing the incomes of each and every person in India.

Sample is a part of a population.

In the above example the following would be some possible samples:

  1. The annual incomes of all the people in Mumbai.

  2. The annual incomes of all the people in India over forty years of age.

  3. Your own annual income (assuming you are in India).

  4. The annual incomes of the first hundred people mentioned in your telephone directory.

Samples, being smaller in size than their population, are easier to study. Hence, if we want to draw some conclusions about a population, we can do so by studying a suitable sample of the population.

Example 

In which of the following cases do the samples appear to be suitable for arriving at conclusions about the corresponding populations?

1.

Population

:

Annual income of every person in India.

 

Sample

:

Annual income of randomly selected persons in Mumbai.

 

Answer

:

Not a representative sample because it is Mumbai.

2.

Population

:

Likely customers for an exclusive credit card scheme.

 

Sample

:

Regular commuters on public transport buses.

 

Answer

:

May not be a representative sample because regular commuters on public transport buses may not be in the income range high enough to support an exclusive credit card holding.

The following notations are used to denote population parameters and sample statistics.

 

Population

Sample

Characteristic

Parameter

Statistic

Size

Mean

Standard Deviation

Proportion

N

  μ

  σ

p

n

  1126_computation of covariance ungrouped data2.png

S

  388_sampling.png


Related Discussions:- Sampling

Systematic sampling, Systematic Sampling In Systematic Sampling ...

Systematic Sampling In Systematic Sampling each element has an equal chance of being selected, but each sample does not have the same chance of being selected. Here,

Probability theory, Origin and Development of probability Theory: The c...

Origin and Development of probability Theory: The credit for origin and development of probability goes to the European gamblers of 17 th century. They  used to gamble  on gam

Sdsad, Ask questionsadsadsadsadas#Minimum 100 words accepted#

Ask questionsadsadsadsadas#Minimum 100 words accepted#

Postneonatal mortality rate, Mid year population 440000 Late fatal death...

Mid year population 440000 Late fatal death          29 No. of live birth           5200 No. of infant death      423 No. of maternal death 89 No. of infant deaths i

Make a decision about the claim, Make a decision about the given claim. Do...

Make a decision about the given claim. Do not use any formal procedures and exact calculation. Use only the rare event rule. Claim: A coin favors head when tossed, and there

Create the venn diagram, Create the Venn diagram: A   - you work for a...

Create the Venn diagram: A   - you work for an insurance company.  80% of your company's staff is sales force and 70% of your company's sales is force is male. in your company

Determine best estimates of the population mean and variance, Question: ...

Question: (a) A normal distribution is thought to have a mean of 50. A random sample of 100 gave a mean of 52.6 and a standard deviation of 14.5. A significance test was carri

Prediction, Differentiate between prediction, projection and forecasting.

Differentiate between prediction, projection and forecasting.

Simple linear regression, We are interested in assessing the effects of tem...

We are interested in assessing the effects of temperature (low, medium, and high) and technical configuration on the amount of waste output for a manufacturing plant. Suppose that

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd