Key Concepts in Statistics

Questions and Answers

What is a sample?

An average of all data points

A collection of all outcomes

A measure that describes a population

A subset of a population (correct)

What does a statistic measure?

It describes a sample characteristic.

It is impossible for the Census Bureau to obtain all the census data about the population of the US.

True

What is a population in statistical terms?

The collection of all outcomes, responses, measurements, or accounts that are of interest. Signup and view all the answers

Is the height of each student in a classroom a population or a sample?

Population Signup and view all the answers

Are the ages of three families of people in an apartment building a sample or a population?

Sample Signup and view all the answers

Who are considered the population in a survey of 1003 adults regarding federal tax dollars?

All adults in the county. Signup and view all the answers

Identify the sample in the problem with 1003 adults selected.

The 1003 adults selected. Signup and view all the answers

What is a parameter in statistics?

Numerical summary of population. Signup and view all the answers

What does a statistic indicate?

Numerical summary of sample. Signup and view all the answers

What is a census?

A study of the health of 146 heart transplant patients at a hospital. Signup and view all the answers

What does 'simple random' mean in sampling?

Each possible sample of a given size is equally likely to occur. Signup and view all the answers

What is stratified sampling?

Sample is obtained by separating the population into non-overlapping groups and obtaining a simple random sample from each group. Signup and view all the answers

How is systematic sampling conducted?

By selecting every KTH individual from the population. Signup and view all the answers

What characterizes cluster sampling?

Obtained by selecting individuals from randomly selected groups of individuals. Signup and view all the answers

What defines convenience sampling?

It is a sample in which the individuals are easily obtained. Signup and view all the answers

If percentages are used, the sum of a frequency distribution should be ____.

100% Signup and view all the answers

What is a frequency distribution term?

The class with the distance between the lower and upper limits of consecutive classes. Signup and view all the answers

Study Notes

Key Concepts in Statistics

Sample: A subset of a larger population used to make inferences about that population.
Statistic: A numerical measure that describes characteristics of a sample.
Population: The complete set of outcomes, responses, or measurements of interest.
Parameter: A numerical summary that describes a characteristic of an entire population.

Differentiating Between Sample and Population

Height in Classroom: The heights of all students in a classroom represent a population.
Ages of Families: The ages of three families in a building represent a sample of the wider group of all residents.

Examples of Populations and Samples

Adults in County: The population includes all adults in the county being surveyed about federal tax dollars.
Selected Adults: The sample consists of the specific 1003 adults surveyed in that county.

Types of Sampling Methods

Census: A complete collection of data for a specific population (e.g., study of heart transplant patients).
Simple Random Sampling: Each possible sample of a specified size has an equal chance of selection.
Stratified Sampling: The population is divided into non-overlapping groups, and a simple random sample is drawn from each.
Systematic Sampling: Selecting every Kth individual from a population to form the sample.
Cluster Sampling: Involves selecting entire groups randomly instead of individuals.
Convenience Sampling: Involves choosing individuals that are easily accessible.

Understanding Frequency Distributions

Total Percentages: When using percentages, the total should equate to 100%. When using proportions, the total should equal one.
Class Width: Refers to the range between lower and upper limits of consecutive classes within a frequency distribution.

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Description

This quiz covers fundamental concepts in statistics, including definitions and differences between samples and populations. Explore various sampling methods and learn how to differentiate between populations and samples using relevant examples.