Transcript Notes 2.2 (Part 1)

Notes 2.2 (Part 1)
Descriptive statistics: More graphs
and displays
What you should learn
• 1. How to graph and interpret quantitative
data sets using stem and leaf plots and dot
plots.
• 2. How to graph and interpret qualitative
data sets using pie and Pareto charts.
• 3. How to graph and interpret paired data
sets using scatter plots and time series charts.
Pie Chart
• Convenient way to present qualitative data
• To create this graph you must have a class,
frequency, relative frequency and angle
columns.
Class
Honda
BMW
Lexus
∫
60
130
170
∑∫ =
Relative Angle
∫
Class
Honda
BMW
Lexus
∫
60
130
170
∑∫ = 360
Relative Angle
∫
.17
.36
.47
To obtain angle
• To obtain angle you must multiply the relative
frequency by 360. (Round the answer
appropriately to the nearest whole number)
• Honda .17 (360) = 61.73 = 62
• BMW .36 (360) =
• Lexus .47 (360) =
To obtain angle
• To obtain angle you must multiply the relative
frequency by 360. (Round the answer
appropriately to the nearest whole number)
• Honda .17 (360) = 61.73 = 62
• BMW .36 (360) = 129. 6 = 130
• Lexus .47 (360) =
To obtain angle
• To obtain angle you must multiply the relative
frequency by 360. (Round the answer
appropriately to the nearest whole number)
• Honda .17 (360) = 61.73 = 62
• BMW .36 (360) = 129.6 = 130
• Lexus .47 (360) = 169.2 = 169
Class
Honda
BMW
Lexus
∫
60
130
170
∑∫ = 360
Angle column should add up
to around 360. It might be off
by a few degrees as a result
of rounding
Relative Angle
∫
.17
62
.36
130
.47
169
Try it yourself 1
• Construct a table a pie chart
Vehicle type
Cars
Trucks
Motorcycles
Others
killed
(∫)
25
9
3
1
Relative
∫
Angle
Assignment #18
• Pg 54
13, 20, 21
Notes 2.2 (Part 2)
Stem and Leaf and Dot Plots
Stem and Leaf plot
• A newer and easier way of displaying data
• Each number is separated into two parts, the
stem (which are the left most digits of a
number) and the leaf (which is the last digit in
the number)
• Stem side must be in order from least to
greatest and you cannot skip a number even if
no numbers have that stem
Stem and leaf example
• 10, 41, 22, 11, 10, 14, 18, 20, 47,28, 24, 14
1
2
3
4
| 0, 1, 0, 4, 8, 4
| 2, 0, 8, 4,
|
| 1, 7
Unordered Stem and leaf plot
Stem and leaf example
• 10, 41, 22, 11, 10, 14, 18, 20, 47,28, 24, 14
1
2
3
4
| 0, 0, 1, 4, 4, 8
| 0, 2, 4, 8
|
| 1, 7
Ordered Stem and leaf plot