Question

Random, systematic, convince, stratified, or cluster

1) The sexuality of women was discussed in Shere Hite’s book Women and Love: A Cultural Revolution. Her conclusions were based on sample data that consisted of 4500 mailed responses from 100,000 questionnaires that were sent to women.

2) When collecting data from different sample locations in a lake, a researcher use the “line transect method” by stretching a rope and collecting samples at every interval of 5 meters.

3) In a study of treatments for back pain, 641 subjects were randomly assigned to the four different treatment groups of individualized acupuncture, standardized acupuncture, and usual care.

4) The author collected sample data by randomly selecting 20 different pages from a printed version of the Merriam-Webster Dictionary and then counting the number of defined words on each of those pages.

5) On the day of the last presidential election, ABC News organized an exit poll in which specific polling stations were randomly selected and all voters were surveyed as they left the premises.

6) The New York State Department of Transportation evaluated the quality of the New York State Throughway by testing core samples collected at regular intervals of one mile.

Answer 1

Step 1:

(1)

Simple random sample:

Simple random sample refers to sampling method which has following properties.

1) The population consist of objects.

2) The sample consist of objects.

3) If all possible sample of objects are equally likely to occur, the sampling method is called simple random sample.

Here the topic of study is sexuality of women.

Here the number of women sent questionnaires are .

The sample of response received consists of mails.

Every questionnaires has only one response.

So here the possible sample of received response is equally likely.

The type of sampling used here is Simple random sampling.

Step 2:

(2)

Systematic sample:

With systematic random sampling, create a list of every member of the population.

From the list, we randomly select the first sample element from the first  elements on the population list.

Thereafter, we select every element on the list.

Here the sample of collecting data of the lake is repeated for every 5 meters.

The type of sampling used here is Systematic random sampling.

Step 3:

(3)

Stratified sample:

A stratified sample is a population sample that requires the population to be divided into smaller groups, called strata.

Here in the study of back pain treatments, 641 subjects are divided into four different treatment groups.

The type of sampling used here is Stratified sampling.

Answer 2

Contd...

Step 4:

(4)

Convenience sample:

A convenience sample is one of the main types of non- probability sampling method.

A convenience sample is made up of people who are easy to reach.

Here we randomly select 20 different pages from  a printed version of Merriam-Webster Dictionary.

The type of sampling used here is convenience sampling.

Step 5:

(5)

Cluster sample:

A cluster sample is a population sample that requires the population to separate groups, called clusters.

Here the ABc news organized an exit poll in which specific polling stations were randomly selected and all voters were surveyed as they left the premises.

So first we have selected polling stations and then the survey is made.

The type of sampling used here is cluster sampling.

Step 6:

(6)

Systematic sample:

With systematic random sampling, create a list of every member of the population.

From the list, we randomly select the first sample element from the first  elements on the population list.

Thereafter, we select every element on the list.

The transportation quality of New york state was evaluated by collecting core samples collected at regular interval of time.

Solutions:

(1) Simple random sampling.

(2) Systematic random sampling.

(3) Stratified sampling.

(4) Convenience sampling.

(5) Cluster sampling.

(6) Systematic random sampling.