Transcript lowest value ex. Data is 2 5 7 14 19 Range = 19

Graphs
V. Data Analysis
A. Range
1. Total value your data covers from lowest
to highest
2. Range = highest value – lowest value
ex. Data is 2 5 7 14 19
Range = 19 – 2 = 17
B. Average
1. The mean of all the data values
collected
2. Avg = total of values
# of values added
ex: Data is 2 5 7 14 19
Avg = 2 + 5 + 7 + 14 + 19 = 47 = 9.4
5
5
VI. Graphs
A. Visual way to organize and analyze data
B. Types of graphs:
1. Line
2. Bar
3. Pie
C. Line graph
1. Used when one
variable causes a
second variable to
increase or decrease
in value
2. Often show
changes over time
D. Bar graph
1. Compares
categories of
information
2. Good for surveys
E. Pie graphs
1. Compares categories
of information usually
written in percent
2. Slices must add
up to 100%
Practice: Name these graph types
Chart #1
Chart #2
100
80
60
1st Qtr
2nd Qtr
3rd Qtr
4th Qtr
East
West
North
40
20
0
1st Qtr 2nd Qtr 3rd Qtr 4th Qtr
Chart #3
100
80
East
West
North
60
40
20
0
1st Qtr
2nd Qtr 3rd Qtr
4th Qtr
4.Which type of graph and why?
Dog Breed
Golden Retrievers
German Shepherd
Beagle
Poodle
Rottweiler
% of dog owners who
own this
breed of dog
30%
20%
20%
20%
10%
Pie Graph
Percent with total adding up to 100%
5. Which type of graph and why?
First Name
Jasmine
Alejandra
Kenji
Lola
Jordan
Bar graph
Comparison survey
# of Letters
7
9
5
4
6
F. Variables
1. Independent variable – variable
that might influence another
variable
a. scientist changes
b. always on x-axis (horizontal
line)
2. Dependent variable – variable
influenced by independent variable
a. Always on y-axis (vertical line)
b. No one controls
G. Making a line graph
1. Choose variables for your x and y-axis
a. x variable causes change in y variable
b. Label your axes with titles, numbers, and
units
2. Make a scale
a. Scale = range  # of boxes = # data units
per graph box
3. Plot your data
4. Create a descriptive title putting the y variable
first
Practice
A student counted the
total number of leaves in
a group of duckweed
plants over a 5 day
period. Copy this data
into your notes.
Days
0
Number of
Leaves
15
1
20
2
25
3
40
4
60
5
80
1. What is the
independent variable?
2. Which axis does it go
on?
3. What is its range?
4. On a 10 x 10 box
0 1 2 3 4 5 6 7 8
grid, what is its scale?
Days
5. Number and label your
axis.
Number of Leaves
6. What is the
dependent variable?
7. Which axis does it go
on?
8. What is its range?
9. On a 10 x 10 box
grid, what is its scale?
10. Number and label
your axis.
100
90
80
70
60
50
40
30
20
10
0
11. Now plot your data points and draw a
straight line through them.
12. Write a descriptive title for this graph.
13. When would the plants have 35 leaves?
14. How many leaves would the plants have
after 7 days?
H. 3 Types of Graphing
Relationships
1.Direct Relationship
a. When one variable
increases, the other
increases.
b. If one variable decreases,
so does the other one.
c.  or  
draw this as example 
2. Inverse Relationship
a. When one variable
increases, the other
decreases
b. 
draw this as
example 
3. No Relationship
a. Data points are
scattered all over
draw this as
example 
Direct
Inverse