Data Collection Methods and Populations

Questions and Answers

What is the correct definition of a population in statistics?

A group of elements selected for study.

The average of a variable measured in a sample.

The complete set of entities we are interested in. (correct)

A measurement taken from a specific sample instance.

Which of the following correctly describes a sample?

It is a part of a population used for data collection. (correct)

It includes all entities from a population.

It is always equal in size to the population.

It cannot be used to infer information about a population.

What does the term population size (N) refer to?

The average value of a variable in the population.

The number of samples taken from a population.

The total number of elements in the population. (correct)

The number of variables measured in a sample.

If a sample consists of 50 students selected from a university, how is this group defined?

A sample of a population. Signup and view all the answers

What does the sample size (n) represent?

The number of elements in the sample. Signup and view all the answers

Which of the following is NOT a source of data?

Theoretical models Signup and view all the answers

Study Notes

Sources of Data

Routinely kept records provide ongoing, organized data collection.
Surveys gather information directly from a sample of individuals or groups using questionnaires.
Experiments allow for controlled observations and data collection under specific conditions.
External sources, such as published reports and databases, offer pre-existing data for analysis.

Population

Defined as the entire group of entities or individuals of interest at a specific time.
Measurements taken from each entity produce a set of values, collectively known as the population of that variable.
Example demonstrates a population of weights from all selected university students, highlighting the variable of interest in this case.

Population Size (N)

Represents the total number of elements in a population, denoted as N.
Understanding population size is critical for determining the scope and scale of the analysis.

Sample

A sample is a subset selected from the larger population for data collection.
Represents a smaller portion of the population that is examined to draw conclusions about the whole population.
Example illustrates that weights from 50 randomly selected university students form a sample, allowing focused analysis.

Sample Size (n)

The number of elements in a sample is referred to as the sample size, denoted by n.
Sample size plays a vital role in statistical analysis, influencing the reliability and accuracy of conclusions drawn from the data.

Description

Explore the various sources and methods of data collection, including records, surveys, and experiments, and understand the importance of population and sample size in analysis. This quiz will highlight key concepts related to defining populations and selecting samples.