Statistics 211 Flashcards

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Questions and Answers

What are individuals in a study?

Objects that are not part of the study

The people or objects included in the study (correct)

Only the people in a study

None of the above

What is a variable?

A characteristic of the individual to be measured or observed

Define quantitative variable.

A variable with a value or numerical measurement for which operations such as addition or averaging make sense

What describes a qualitative variable?

A variable that describes an individual by placing them into a category or group Signup and view all the answers

What is population data?

Data from every individual of interest Signup and view all the answers

What is sample data?

Data from only some of the individuals of interest Signup and view all the answers

What does a population parameter refer to?

A numerical measure that describes an aspect of a population Signup and view all the answers

What is a sample statistic?

A numerical measure that describes an aspect of a sample Signup and view all the answers

Define statistics.

The study of how to collect, organize, analyze, and interpret numerical information from data Signup and view all the answers

What does nominal level data consist of?

Names, labels, or categories with no implied criteria Signup and view all the answers

What is ordinal level data?

Data that can be arranged in order, but where differences between data values cannot be determined or are meaningless Signup and view all the answers

Define ratio level data.

Data that can be arranged in order and has a true zero Signup and view all the answers

What is interval level data?

Data that can be arranged in order and where differences between data values are meaningful Signup and view all the answers

What is descriptive statistics?

Methods of organizing, picturing, and summarizing information from samples or populations Signup and view all the answers

What is inferential statistics?

Methods of using information from a sample to draw conclusions regarding the population Signup and view all the answers

What is an example of a ratio variable?

Length of time to complete an exam Signup and view all the answers

What type of variable is the time of first class?

Interval Signup and view all the answers

Define a stratified sample.

A sample that divides the entire population into distinct subgroups called strata Signup and view all the answers

What is a convenience sample?

A sample created using data from a population that is readily available Signup and view all the answers

Which of the following describes a systematic sample?

Every kth member from a population is included in the sample Signup and view all the answers

What is a sampling error?

A difference between measurements from a sample and corresponding measurements from the respective population Signup and view all the answers

What is a non-sampling error?

The result of poor sample design Signup and view all the answers

What is the purpose of a frequency table?

To partition data into classes or intervals and show how many data values are in each class Signup and view all the answers

Class boundaries are possible data values.

False Signup and view all the answers

What does an outlier in a dataset represent?

A data value that is very different from the other measures Signup and view all the answers

What is a Pareto Chart?

A bar graph where the height of the bars represents the frequency of an event, ordered from decreasing height Signup and view all the answers

Define a circle chart or pie chart.

A chart where wedges visually display proportional parts of the total population sharing a common characteristic Signup and view all the answers

What is a stem and leaf display?

A method of exploratory data analysis to rank-order and arrange data into groups Signup and view all the answers

What is skewness in data?

The direction of asymmetry in a distribution, being either left or right Signup and view all the answers

Match the data types with their definitions:

Nominal = Names, labels, or categories Ordinal = Can be arranged in order but differences are meaningless Interval = Arranged in order with meaningful differences Ratio = Arranged in order with a true zero Signup and view all the answers

Study Notes

Key Concepts in Statistics

Individuals: Refers to the subjects or objects involved in a study, crucial for data collection.
Variable: A measurable or observable characteristic of individuals within a study.
Quantitative Variable: Represents numerical values where mathematical operations such as addition or averaging are applicable.
Qualitative Variable: Categorizes individuals into groups based on characteristics (e.g., gender).
Population Data: Comprehensive data collected from every individual of interest.
Sample Data: Data obtained from a select number of individuals within a population.
Population Parameter: A numerical summary that describes a specific feature of a population.
Sample Statistic: A numerical summary derived from a sample, used to estimate population parameters.

Levels of Measurement

Nominal Level: Data categorized by names or labels with no inherent order.
Ordinal Level: Data arranged in order, but the differences between values are not meaningful.
Interval Level: Data that can be ordered with meaningful differences between values, but lacks a true zero.
Ratio Level: Similar to interval data but includes a true zero, making all mathematical operations valid.

Statistical Methods

Descriptive Statistics: Techniques for organizing and summarizing data to describe sample or population characteristics.
Inferential Statistics: Techniques that allow conclusions about a population based on sample data.

Types of Samples

Simple Random Sample: Every individual has an equal chance of being selected from the population.
Stratified Sample: Population divided into subgroups (strata) based on specific characteristics before sampling.
Systematic Sample: Selection of individuals at regular intervals from an ordered list, starting from a random point.
Convenience Sample: Utilizes readily available data to create a sample, potentially introducing bias.
Cluster Sample: Population divided into clusters, and entire clusters are selected at random for inclusion in the sample.

Error Types in Sampling

Sampling Error: Discrepancies between sample measurements and actual population metrics.
Non-sampling Error: Errors arising from poor sample design or implementation.

Data Organization

Frequency Table: A method to organize data into classes or intervals, showing the frequency of each class.
Class Boundaries: Values defining the limits of data classes, established by adjusting class limits.

Data Visualization

Pareto Chart: A bar graph that displays the frequency of events, arranged in descending order.
Pie Chart: Visual representation of data where wedges represent proportions of a whole.
Time Series Graph: Displays data points over time at regular intervals.
Stem-and-Leaf Display: A method for organizing data that preserves the original values while facilitating analysis.

Data Distribution

Mound-shaped Symmetrical: A distribution where both sides are identical when folded vertically; often bell-shaped.
Uniform Distribution: All classes have equal frequency, creating a flat histogram.
Skewness: Indicates the direction of the tail in a distribution; skewed left or right.
Bimodal Distribution: A histogram with two classes that have the largest frequencies separated by at least one class.

Class Limit vs. Class Boundary

Class Limits: Possible data values defining the span of a class.
Class Boundaries: Values that fall between class limits, typically not representing actual data values.

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Test your knowledge on key concepts in Statistics 211 with these flashcards. This quiz covers important terms such as individuals, variables, and types of variables in statistics. Boost your understanding and retention of statistical terminology!