
What is a historgram
graph that summarizes data

Distribution Table
Show the percentage distribution between class intervals.

Endpoints
01000 the Class from 0 to 1000 is included anything over a 1000 is placed in the next interval.

Plotting Percentages
Be sure to divide intervals by the percentages
 Example
 01000 10%
 10002000 10%
 20003000 7%
 30005000 15% (Divide 15% x 2 intervals, which will equal 7.5%)
 700010000 15% (Divide 15% x 3 intervals, which will equal 5%)

Height of a Block
To figure out the height of a block over a class interval, divide the percentage by the length of the interval
 example:
 70001000 = 15% () = Height of 5%

Area of Histogram Block
The area of a block is always going to be ( ) or (for triangles)
 Length = Intervals
 Height = Usually Percentage
example:
Interval = 700010000 Height = 15% (for total area)
area = 15 % X 3 intervals (7k10k) = 45% area


Qualitative
 Single
 Marital Status
 Widowed
 Divorced
 Separated
NOT DISCRETE OR CONTINUIOUS

Quantitative
 Age
 Family Size
 Family Income
 Height
 Weight
BOTH ARE DISCRETE AND CONTINUOUS

Discrete
The value can only vary by fixed amounts
0,1,2,3 and so on nothing can be in the middle.
Example of this would be a family size.

Continuous
Values lie in between variables.
Example of this would be age and weight. The difference are minute. In age a person can be a minute, hour, day, week month, or year older than another subject.

The Density Scale
Represents crowing of blocks within a histogram

Cross Tabulation
Different Groups (Tabs) are made and compared
i.e. User and nonuser.

Selective Breeding
Selecting Breeding consist of breeding certain people or mice based on favorable characteristics
I.e. Intellegence, Physical ability...
pg. 48

