1. Showing patterns & trends
Graphing Your Data
Showing patterns & trends
A picture is worth a thousand words!

2. Types of data (information)
Variables
what you measure in an experiment
dependent variable
What is measured
unpredictable change: we don’t know how it will change until we do the experiment
Y-axis
independent variable
What is changed variable
predictable change: it only changes because we chose how it would change
X-axis
The effect of _____________ on _____________
INDEPENDENT
DEPENDENT

3. Examples of experiments 1
How does fertilizer affect the growth rate of plants?
we set up an experiment testing different amounts of fertilizer on different plants & measuring the growth (height) of the plants:
dependent variable (Y-axis)?
height of plants
independent variable (X-axis)?
amount of fertilizer
The effect of _____________ on _____________
Amount of Fertilizer
Height of Plants

4. Examples of experiments 2
How does exercise affect heart rate of 10th grade student?
we set up an experiment testing different lengths of time of exercise (minutes) on the heart rate of students:
dependent variable (Y-axis)?
heart rate
independent variable (X-axis)?
minutes of exercise
The effect of _____________ on _____________
Exercise
Heart Rate

5. Examples of experiments 3
What’s the favorite drink of students?
we set up an experiment surveying students and asking which is their favorite drink :
dependent variable (Y-axis)?
number of students
independent variable (X-axis)?
type of drink
The effect of _____________ on _____________
Type of Drink
How many students chose it

6. The Dependent Variable is dependent on the Independent Variable
The Dependent Variable is dependent on the Independent Variable! Which is which? Growth of Plant Amount of Light

7. Making pictures out of data
Graphs
line graphs
graphing data that shows continuous change
bar graphs (or histograms)
graphing data that is in disconnected groups
The bars touch for a histogram and are separated for a bar graph
How’s a critter to choose?

8. elevation (feet above sea level)
How does elevation affect temperature?
Line graph!
elevation (feet above sea level)
temp.
(°C) 30
500 25
1000 20
1500 15
2000 10
2500 5 30 25 20 18
temperature 15 10
1200 ft? 5
500
1000
1200
1500
2000
2500
elevation

9. Which drink do you like best?
number
Coke 1
Pepsi
Water 4
Iced tea
Gatorade 3 6
Bar graph! 5 4
number of students 3 2
Red Bull? 1
Coke RB
Pepsi RB
water
tea
Gatorade
type of drink

10. We took a tally of how many students like each kind of pop… Make a bar graph to show the results
Pepsi 15
Coca Cola 12
7-Up 4
Mountain Dew 8
Root Beer 2
Cherry Coke 7
Dr. Pepper 5

11. This table shows how student attendence effects their grades… Make a line graph of the data
Number of Days Missed during year
Regents Exam Grade 5 88 10 80 14 74 22 68 36 55 50 52 78 34

12. Questions: (write this on your graph paper)
What is the independent variable?
Number of days absent
What is the dependent variable?
grade
What is the relationship between number of days missed and grade?
As the number of days absent increases, Exam grade decreases!