stat chapter3-4

Actual data that we collect from surveys,

observations, and experiments

• Raw data

• Array

Ordered arrangement of data according to magnitude

(a)  

a way of summarizing data by showing the number of

observations that belong in the different categories or

classes

(a)  

is used for data that can be placed in specific

categories, such as nominal- or ordinal-level data

• Categorical frequency distribution

• Numerical frequency distribution

• Single value grouping

• Grouping by class intervals

A frequency distribution where the classes are the

distinct values of the variable

Applicable for data with only a few unique values

• Categorical frequency distribution

• Numerical frequency distribution

• Single value grouping

• Grouping by class intervals

A frequency distribution where the classes are the intervals

• Categorical frequency distribution

• Numerical frequency distribution

• Single value grouping

• Grouping by class intervals

is the range of values that belong in the

class or category.

(a)  

is the number of observations that

belong in a class interval.

(a)  

are the end numbers used to define the

class interval.

(a)  

are the true class limits.

(a)