1.1 Flashcards
Intro to the practice of stats
Population
The entire group to be studied
Sample
A subset of the population that is being studied
Individual
A person or object that is a member of the population
Variable
The characteristics of the individual within the population
Data
The list of observed values for a variable
Statistics
A numerical summary of a sample
S=S
Parameter
A numerical summary of a population
P=P
Descriptive statistics
Summarizing and organizing data
Inferential statistics
Extends the result from a sample to the population and measures the reliability of the results
Qualitative variable
Places the individual into a group or class
Not discrete/continuous
Quantitative Variable
Has a value or numeric measurement
Discrete
The variable has either a finite (limited) number of possible values or a countable number of possible values
COUNTABLE
Continuous
The variable has an infinite number of possible values that are not countable
NOT countable
Nominal level
Data can be put into categories
“In name only”
Names, labels, or categories
Example: The color of vehicles on a dealer’s lot
you can’t really do anything with it
Qualitative
Ordinal level
Data can be ordered
Comparisons are only relative
Example: Class rank (freshman, sophomore, ect)
Qualitative
Interval level
Data can be ordered
meaningful difference can be computed
A value of zero does not mean the absence of the quantity
Example: Air temperature, calendar dates
Zero is not always an issue
Quantitative
Ratio levels
Data can be ordered
Meaningful differences can be computed
Meaningful ratios can be computed
A value of zero MEANS the absence of the quantity
Example: A person’s income
Quanitiative
