Intro to Statistics Flashcards 1.1

Questions and Answers

Define Statistics.

Statistics is the science of collecting, organizing, summarizing, and analyzing information to draw a conclusion and answer questions.

A(n) _________ is a person or object that is a member of the population being studied.

individual

A(n) is a numerical summary of a sample, and a(n) is a numerical summary of a population.

statistic; parameter

What are variables?

Variables are the characteristics of the individuals within the population. Signup and view all the answers

Is the numerical value '21' in a phone survey of 100 random houses a parameter or a statistic?

Statistic Signup and view all the answers

What is the difference between a parameter and a statistic?

A parameter is a numerical description of a population characteristic, while a statistic is a numerical description of a sample characteristic. Signup and view all the answers

Determine if the variable 'color of a car driven' is qualitative or quantitative.

Qualitative Signup and view all the answers

Determine if the quantitative variable 'frequency of a guitar note' is discrete or continuous.

Continuous Signup and view all the answers

What is the difference between a discrete and continuous variable?

A discrete variable has a finite or countable number of values, while a continuous variable has an infinite number of possible values that are not countable. Signup and view all the answers

Determine if the variable 'points scored in a college basketball game' is discrete or continuous.

Discrete Signup and view all the answers

What is the level of measurement of the variable 'favorite film'?

Nominal Signup and view all the answers

What is the level of measurement of the variable 'highest degree conferred'?

Ordinal Signup and view all the answers

Define an ordinal variable.

A variable is at the ordinal level of measurement if it has the properties of the nominal level and allows for values to be arranged in a ranked order. Signup and view all the answers

Define a nominal variable.

A variable is at the nominal level of measurement if it names, labels, or categorizes without allowing for rankings. Signup and view all the answers

Define an interval variable.

A variable is at the interval level of measurement if it has the properties of ordinal measurement and the differences in values have meaning, but a value of zero does not mean absence. Signup and view all the answers

Define a ratio variable.

A variable is at the ratio level of measurement if it has the properties of interval measurement and the ratios of values have meaning, with zero indicating absence. Signup and view all the answers

In a study contacting 1162 adults aged 20 to 90, what is the population?

Adults who are 20 to 90 years of age and live in Europe. Signup and view all the answers

In the duct tape versus cryotherapy study, what is the sample?

The 60 patients with warts. Signup and view all the answers

What identifies the research objective of the duct tape and cryotherapy study?

To determine if duct tape is as effective as cryotherapy in treating warts. Signup and view all the answers

List the descriptive statistics from the duct tape versus cryotherapy study.

50% of patients in group 1 and 40% of patients in group 2 with complete resolution. Signup and view all the answers

What was the conclusion of the duct tape versus cryotherapy study?

Duct tape is significantly more effective than cryotherapy in treating warts. Signup and view all the answers

In the context of analyzing zip codes, what is the level of measurement of 'zip code'?

Nominal Signup and view all the answers

Does the level of measurement of the variable 'zip code' change when associating it with population density?

Yes, it changes to ordinal. Signup and view all the answers

What is the research question addressed in the study about protein levels when the heart is stressed?

How is the level of a certain protein associated with a person's health? Signup and view all the answers

Identify the population in the protein study.

All people. Signup and view all the answers

In the protein study, what is the sample?

The 1034 patients in the study. Signup and view all the answers

What are the descriptive statistics from the protein study?

People with the highest levels of the protein were 33 times more likely to die than those with the lowest levels. Signup and view all the answers

What are the inferences of the protein study?

Higher levels of the protein are associated with worse outcomes. Signup and view all the answers

Study Notes

Introduction to Statistics

Statistics involves the collection, organization, summarization, and analysis of information to draw conclusions and answer questions, including confidence measures in findings.

Population and Individual

Population refers to the entire group under study; an individual is a member of that population.

Summary Measures

A statistic is a numerical summary derived from a sample, while a parameter is a numerical summary derived from the entire population.

Variables

Variables are characteristics of individuals within a population, with variations necessitating statistical analysis.

Parameter vs. Statistic

An example illustrates a statistic as it describes a characteristic derived from a sample (e.g., the count of families with garages from a sample of households).

Qualitative vs. Quantitative Variables

Qualitative variables categorize characteristics (e.g., car color).
Quantitative variables can be discrete (countable) or continuous (not countable).

Discrete vs. Continuous Variables

Discrete variables have a finite or countable set of values (e.g., points scored in a game), while continuous variables can take an infinite number of values (e.g., frequency of a guitar note).

Levels of Measurement

Nominal: categorizes without order (e.g., favorite film).
Ordinal: categorizes with a ranked order (e.g., highest degree conferred).
Interval: has meaningful differences, but zero does not indicate absence (e.g., temperature).
Ratio: has meaningful ratios, and zero indicates absence, allowing all arithmetic operations (e.g., weight).

Research Studies

Identifying population and sample:
- Population: Adults aged 20-90 in Europe.
- Sample: 1162 adults surveyed.

Research Objectives

Example study objective questioned duct tape's effectiveness compared to cryotherapy for warts treatment.
Sample included 60 patients; descriptive statistics showed success rates of treatments.
Conclusions indicated duct tape's superiority.

Importance of Variable Definition

Clearly defining variables impacts analysis type; zip code is nominal, but if viewed in terms of population density, it changes to ordinal.

Health Outcome Study

A study measured protein levels' impact on health over seven years, revealing higher protein levels were significantly associated with increased mortality risk.
Addressed research questions focused on protein levels' correlation with health outcomes. Population included all individuals; the sample consisted of 1034 patients, with descriptive statistics highlighting the strong mortality association linked to protein levels.

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Description

Test your knowledge with these flashcards covering the basics of statistics. This set focuses on key definitions and concepts essential for understanding statistical analysis. Perfect for anyone beginning their journey in statistics!