1. Interpreting Graphs

2. Why bother with graphs at all?
Graphs are a quick way to make comparisons and see trends.

3. Which job would you prefer to have?

4. Types of Graphs
Line Graph  - usually shows change over time
Bar  Graph  -  compares values
Pie Graph - shows parts of a whole
Scatter Plot - shows trends

5. In this example, an employee counted the number of swimmers at a local pool at the 15th of each month at 1pm.  One line is used to represent a change over time. 
How many swimmers were there in May? ___
In August? ____
Overall, the trend shows that the number of swimmers is greatest during what month(s)?
__________

6. Sometimes, more than one line can be placed on the same graph
Sometimes, more than one line can be placed on the same graph.   Again, the time component is listed on the X axis.
----  chocolate
----- vanilla
---- red velvet
What is the most popular flavor of cupcake?
ITEMS SOLD

7. How to build a line graph
Data
Day g
Day g
Day 10  - 80 g
Day g
Day g
How to build a line graph
If there is a time or trial aspect, place that number on the X axis.   ***Numbers should be evenly spaced.
The dependent or responding variable goes on the Y axis.

8. Sometimes, the data is not in order, your graph must put the data in order and decide how to space your graph.
Temperature & Number of cricket chirps
22 degrees = 22 chirps
25 degrees = 26 chirps
19 degrees = 20 chirps
12 degrees = 8 chirps
18 degrees = 16 chirps
10 degrees = 4 chirps
Temperature - goes from 10 to 25

9. If time isn't one of the factors, you will need to decide what to put on the X and the Y axis.   Generally, the X axis has the independent variable (what you adjusted) and the Y has the responding variable (what is measured).
A cart is pushed down a track with different weights on it.  How far the cart travels is measured.
Weight        Distance
4   kg              140 m
8   kg              120 m
12   kg            100 m 16 kg              80 m 20  kg             60 m
24 kg              40 m 26 kg              20 m
Weight of Car

10. The graph you created shows an INVERSE RELATIONSHIP
As a factor increases, the other factor decreases
More examples
As you increase your velocity, the time spent to get to your destination decreases
If you eat more vegetables, your risk of a heart attack decreases
Increasing the weight, will decrease the distance traveled. 

11. Direct relationships occur when the two variables go up or down together.
Examples:
Increasing the temperature increases the heart rate of a frog
As the radius of a pipe increases, the flow of water through the pipe also increases

12. Pie Graphs and Bar Graphs are used to COMPARE values.
What is the heart rate of a chicken?  ___________
What is the heart rate of a rabbit? ___________
What animal has the highest heart rate? ________
What animal has the lowest heart rate? ________
What two animals have the closest heart rates? ___________

13. What is this bar graph telling you?

14. What activity does this person spend the least amount of time on
What two activities are closest in hours spent? 
____________________________________

15. Bar graphs are easy to make, but pie graphs require a COMPASS and PROTRACTOR to measure angles
Make a pie graph of the colors of shirts being worn today.

16. Scatterplots are graphs that don't use lines
Scatterplots are graphs that don't use lines..they show how points are "scattered" around variables.  Sometimes lines can be made that "fit" the plots.

17. What do each of the dots represent?  _______________
What is the relationship between antenna and leg length?  ___________
The cricket with the shortest antenna had what length of leg? ________
Two crickets had 10 mm long antenna.  What were their leg lengths?  _______ Can you fit a line to the dots?  _______

18. For each of the descriptions, determine what type of graph is best (line, bar, or scatterplot)
1.  To show how the numbers of catfish increased over a 10 year period. ____________
2.  To compare average test scores of 9th, 10th , 11th and 12th graders.  ______________
3.  To analyze the relationship between height and weight among high school freshmen. _____________
4.  To show the proportion of students in a class that are in each age group (15, 16, 17, 18) ________________
5.  To compare the salaries of 5 different professions – doctor, lawyer, teacher, cashier, accountant.   __________

19. QUIZ TIME - GRAPHING

20. 1. This type of graph is used to show a change over time
1.  This type of graph is used to show a change over time.  Like how many frogs were found in a pond throughout the summer months:  _____________________
2.  You might need a compass and a protractor to make this kind of graph: ___________________
3.  What is this type of graph called?         _________________    
4.  In crocodiles, as the temperature decreases, the number of females hatched increases.  This is an example of an _____________________  relationship.
5.  On a graph, time is usually placed on the [ X  /  Y  ] axis.

21. 6.  In this type of graph, a line is created that "fits" the dots:
          _____________________________
7.   When two variables go up at the same time, it is called a _____________________  relationship.
Ex.  As the temperature goes up, the number of mosquitoes goes up.
8.  What kind of graph is this?
9.  What type of graph would be used to COMPARE the number of animals at the zoo?   (Ex. 10 zebra, 4 elephants, 6 lions..)
10.  On the back of your strip, make a mini graph using the zoo data from #9