Sampling, Applied Statistics

Assignment Help:

Sampling

A 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.

A 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

Mean and median, The amounts of money won by the top ten finishers in a fam...

The amounts of money won by the top ten finishers in a famous car race are listed below. $1,172,246    $163,659    $440,584    $350,634     $290,596 $186,731    $145,809     $143,2

Association of attributes, In an examination 600 candidates appeared, boys ...

In an examination 600 candidates appeared, boys outnumbered girls by 16% of all candidates. number of passed candidates exceeded the number of failed candidates by 310. Boys failin

Find the optimal adaptive meshes for a skewed beta density, Show that the I...

Show that the ISB in a bin containing the origin of the double exponen-tial density, f(x) = exp(-|x|)/2, is O(h 3 ); hence, the discontinuity in the derivative of f does not have a

Empirical mode, Empirical Mode Where mode is ill-defined, its value may...

Empirical Mode Where mode is ill-defined, its value may be ascertained by the following formula based upon the empirical relationship between Mean, Median and Mode: Mode = 3

Logistic regression model, A marketing research firm was engaged by an auto...

A marketing research firm was engaged by an automobile manufacturer to conduct a pilot study to examine the feasibility of using logistic regression for ascertaining the likelihood

Find the probability customers pay their bill in full, The proportion of Am...

The proportion of American Express credit-card holders who pay their credit card bill in full each month is 23%; the other 77% make only a partial or no payment. (a) In a random

Compute a correlation coefficient, A researcher was interested lowering the...

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

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

Use event rule ot estimates the claim, Make a decision about the given clai...

Make a decision about the given claim. Use only the rare event rule, and make subjective estimates to determine whether events are likely. For example, if the claim is that a coi

Hypothesistesting, Apl.send me nots on hypothesis testing sk question #Mi...

Apl.send me nots on hypothesis testing sk question #Minimum 100 words accepted#

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