Transcript The Vocabulary of Statistics: Part 1

Vocabulary of Statistics
Part One
Stastistics

Original word came from:
State Arithmetic
Variable

A characteristic or attribute that can
assume different values.
example: What color shoes are you
wearing?
 example: How many times a week do you
eat fruit?

Data

The values (measurements or
observations) that the variables can
assume.
Example: I am wearing a green shirt.
 Example: 4 times a week I eat an apple.

Random variables

Where value is determined by chance
Example: Rolling a pair of dice.
 Example: Flipping a coin.

Example
Suppose that an insurance company studies its records
over the past several years and determines that, on
average, 3 out of every 100 automobiles the company
insures were involved in an accident during a 1-year
period.
What is the variable?
What is the data?
Is the data random?
Data Set

A collection of data values.

Each individual value is called a data value
or a datum
Data can be used in different ways.
The body of knowledge called
statistics is sometimes divided into
two main areas, depending on how
the data are used. The two areas
are:
Descriptive statistics
Inferential statistics
Descriptive Statistics

Used to describe a situation.

U.S. Census – average age, income,
number of children, etc.
Descriptive Statistics

Consists of the collection, organization,
summarization, and presentation of data.
Inferential Statistics

Use of a sample to infer (predict) the
particulars of a population.

Inferential statistics use probability – the
chance of an event occuring.

Probability theory is used in areas like
gaming and insurance.

Population: Consists of all subjects
(human or otherwise) that are being
studied.

Sample: A group of subjects selected
from a population.
Inferential Statistics

Consists of generalizing from samples to
populations, performing estimations and
hypothesis tests, determining relationships
among variables, and making predictions.
Inferential Statistics

If the subjects of a sample are properly
selected, most of the time they should
possess the same or similar characteristics
as the subjects of the population.

Your assignment: Write a paragraph
explaining how you would take a random
sample of people who live in Muskogee.
Keep in mind; you need to devise a
method that will not be biased in any way.