Chapter 1 Flashcards

What is a primary source?

A primary source is original data you collect yourself.

What is a secondary source?

A secondary source is data collected by someone else that you use and it must be reliable.

What is a population?

A population is a set of units that we are interested in studying in.

What is a sample?

A sample is a sub-set of the population.

What is descriptive statistics?

Descriptive statistics uses numbers and graphical methods to look for patterns in a data set and summarize the information revealed.

What is inferential statistics?

Inferential statistics is when you take a sample and make inferences and generalization about a larger group of data.

What is qualitative data?

Qualitative (categorical) data describes qualities or categories.

What is quantitative data?

Quantitative data uses numerical data.

What is discrete data?

A type of quantitative data where it is countable (must have whole numbers).

What is continuous data?

A type of quantitative data where it can be measured (ranges, decimals, temperature etc).

What does it mean to be mutually exclusive?

Events that cannot happen at the same time.

What does it mean to be collectively exhaustive?

All possible outcomes are included.

What is relative frequency?

Out of everyone, what percentage likes or is this?

Ex; 30% of the group likes cherry candy more than raspberry candy.

What is the formula for relative frequency?

Frequency of Outcome / Total Number of Observations = % (All relative frequencies add up to 1)

What is cumulative frequency?

Cumulative frequency is the number of values that are at or below a given value (adding).

What is cumulative relative frequency?

What percentage of the total is at or below this value?

What is the formula for cumulative relative frequency?

Cumulative Frequency / Total Number of Observations = %

Do you total cumulative frequencies?

No, only total frequency and relative frequency.

What does qualitative data have in the table?

Frequency and relative frequency.

Why does qualitative data not have cumulative frequencies?

Because qualitative data consists of categorical values.

What is statistics?

Statistics is the science of data which involves analyzing and interpreting numerical information.

What is an experimental/observational unit?

An experimental unit is an object (person, thing, event) about which we collect data.

What is a variable?

It is a characteristic or property of an individual experimental (or observational) unit in the population.

What is a statistical inference?

A statistical inference is an estimate, prediction, or some other generalization about a population based on information contained in a sample.

What is a measure of reliability?

A measure of reliability is a statement (usually quantitative) about the degree of uncertainty associated with a statistical inference.

What are the four elements of descriptive statistical problems?

1. The population or sample of interest

2. One or more variables (characteristics of the population or sample units) that are to be investigated

3. Tables, graphs, or numerical summary tools

4. Identification of patterns in data

What are the five elements of inferential statistical problems?

1. The population of interest

2. One or more variables (characteristics of the population units) that are to be investigated

3. The sample of population units

4. The inference about the population based on information contained in the sample

5. A measure of the reliability of the inference

What is a designed experiment?

A designed experiment is when a researcher gives a treatment to one group and compares it to a untreated (or control) group.

What is an observational study?

An observational study is when a researcher observes and records data without changing or controlling anything.

What is a representative sample?

A representative sample has the same important characteristics as the population it comes from.

What is a random sample?

A random sample is selected from the population in such a way that every different sample of size n has an equal chance of selection.

What is statistical thinking?

Statistical thinking means using logic and statistics to evaluate data and conclusions, while recognizing that data naturally varies.

What is selection bias?

Selection bias happens when some members of the population have no chance of being chosen, making the sample unfair.

What is nonresponse bias?

Nonresponse bias happens when some people in the sample don’t respond, and their missing answers affect the results.

What is measurement error?

Measurement error happens when the data recorded is inaccurate.

Which type of Frequency Distribution has columns for accumulating data?

Quantitative.

What is a class?

A class is one of the categories into which qualitative data can be classified.

What is the class frequency?

The class frequency is the number of observations in the data set that fall into a particular class.

What is the class relative frequency?

The class relative frequency is the class frequency divided by the total number of observations in the data set.

Class relative frequency = Class Frequency / N

What is the class percentage?

The class percentage is the class relative frequency multiplied by 100.

Class Percentage = (Class Relative Frequency) x 100

What are the graphical methods for qualitative data?

• Bar Graph: Bars show categories; height = frequency, relative frequency, or percent

• Pie Chart: Circle slices show categories; slice size = relative frequency

• Pareto Diagram: Bar graph with categories ordered largest to smallest (left to right)

What are the graphical methods for quantitative data?

• Dot Plot: Each data value is a dot on a number line; repeated values stack

• Stem-and-Leaf Plot: Data split into stems and leaves; preserves actual values

• Histogram: Data grouped into equal-width intervals; bar height = frequency or relative frequency