Objective: To choose appropriate
scales and intervals for graphs.
A
Grid
X-axis and Y-axis
Labels
Title
Books Sold
Number of Books
500
400
300
200
100
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
If in May 550 books were sold instead of
450, what will you have to change in your
graph?



it’s a series of numbers placed at fixed distances to
help label the graph.
You use the range of your data to decide on your scale.
You start a scale at 0 and end at a number greater
than the greatest number in your data.
So in this case your scale will be from 0 to ______.
WHAT IS THE SCALE OF THIS GRAPH?
What is the interval? (Hint: its related to the scale.)
Temperature (in F)
Normal Temperature
(Pittsburgh)
80
70
60
50
40
30
20
10
0
Jan
Feb Mar Apr May Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
INTERVAL
The interval of a graph is the difference between
one number and the next on the scale.
What if we change the interval to 10?
No. of Students
No. of Students
Craft Fair
Craft Fair
Bake Sale
Bake Sale
Car Wash
Car Wash
Carnival
Carnival
0
Carnival
Carnival
Car Wash
Car Wash
Bake Sale
Bake Sale
Craft Fair
Craft Fair
5 10 15 20 25 30 35 40 45 50
0 10 20 30 40 50
SCALE AND INTERVAL
Snowfall (in inches)
Snowfall (Sault Ste.)
33
30
27
24
21
18
15
12
9
6
3
0
Oct
Nov
Dec
Jan
Month
Feb
Mar
Apr
CHOOSE A REASONABLE SCALE AND
INTERVAL FOR THE DATA.
a. 12, 15, 18, 30, 22, 16
Scale: 0 – 35
Interval: 5
B. 50, 100 , 200, 225, 120, 60
Scale: 0 – 250
Interval: 50
CLASS WORK
Pw page 28 Q 1 - 8