1. GRAPHING organize present What is a graph?
A visual way to _______________ and _______________data
organize
present

2. Advantages of Graphs Helps visualize data patterns relationships
____________________
Faster than reading information
Can see ___________ quickly
Understand ______________ between variables
patterns
relationships

3. The three types of graphs are:

4. What does a line graph show?
A measured quantity of change with ___________ or __________
Example: Hourly temperature changes in a day
time
distance

5. When is a bar graph useful?
When combining data from one thing at __________________
Example: monthly rainfall
different times

6. What two things does a pie graph show?
How a quantity can be subdivided
A ____________ between quantities
Examples: Population of a state in the US
Percent of minerals in the crust
comparison

7. X and Y axis

8. Dependent/Independent Variables
Independent Variable – a fixed variable, it is __________________ by the other variables you are trying to measure
Examples – time, age, altitude, distance, etc.
Dependent Variable – is __________ by the independent variable (it DEPENDS on it!)
Examples – temperature, test scores, etc.
NOT changed
What is a variable?
It’s the category you are trying to measure
Ind = variable that is manipulated/changed to affect the other variable
dep = variable that is changed
affected

9. Time spent studying vs. test score
Could your test score have affected/changed the amount you studied the night before? NO
Could how much you studied the night before affect/change your test score? YES
Independent variable = time spent studying
Dependent variable = test score

11. Examples:
A student is curious to find out if how old you are affects how many hours of t.v. you watch daily
A scientist conducts an experiment to test the theory that a vitamin could extend a person’s life-expectancy
For last two examples talk about where each one would go on graph (x/y axis)
A science class is testing whether the amount of sunlight a plant is exposed to affects how tall it gets after one week

12. What is ALWAYS required on a graph?
TITLE!
Labeled x and y axis (with units!)
Proper scale
Key (if using two different sets of data)

13. How to determine a title
Should clearly tell what the graph is about
Galena Samples
Mass (g)
Volume (mL)
5.0 25
9.2 46
14.8 74
18.3
91.5
23.0
118

14. Determining scale Step 1: find the range in values
Greatest value – smallest value = range in values
Step 2: count number of units (squares/boxes) on graph
Each box equals 1 unit
Step 3: divide number of units by the range in values

15. Galena Samples Mass (g) Volume (mL) 5.0 25 9.2 46 14.8 74 18.3 91.5
Step 1: find the range in values
Greatest value – smallest value = range in values
23.0 – 5.0 = 18
Step 2: count number of units on graph
Each box equals 1 unit
There are 36 units
Step 3: divide the number of units by the range in values
36/18 = 2
Every 2 units is 1 gram on graph
Galena Samples
Mass (g)
Volume (mL)
5.0 25
9.2 46
14.8 74
18.3
91.5
23.0
118
Both scales do NOT need to be the same scale on both axes!

16. Determining scale DO NOT
The x and y axis ____________ need to have the same scale
Try to use up as much of the allotted graph space
DO NOT

17. What are some types of change that we could see on graphs?
Increase
Decrease
Increase  decrease  increase
Cycles
No change over time

18. Positive Relationship
As the independent variable increases, the dependent variable ___________
The two variables are directly related –
______ RELATIONSHIP
Examples: age vs. height, mass vs. volume
increases
Direct relationship – an increase in one variable, increases the other variable
DIRECT

19. Negative Relationship
As the independent variable increases, the dependent variable __________
The two variables are indirectly related-
___________ RELATIONSHIP
Example: elevation vs. average temperature
decreases
Variables move in opposite directions!
INDIRECT

20. Constant Relationship
As the independent variable increases, the dependent variable ______________
One variable remains constant –
____________ RELATIONSHIP
Example: time of year vs. rotation speed of Earth
stays the same
STATIC
How tall you are/ how much you grow and whether or not you have a nose

21. Cyclic Relationship pattern CYCLIC
As the independent variable increases, the dependent variables increases and decreases in a __________
Dependent variable goes through cycles –
____________ RELATIONSHIP
Repeatable and predictable
Examples: tides on a beach, phases of the moon
pattern
CYCLIC
Repeatable and predictable

22. What type of relationship does this data represent?
Altitude (ft)
Pressure
1000
650
925
1200
800
1900
698
2500
535
3100
375
3800
200

23. What type of relationship is this?
A scientist wanted to study whether the population of a given area affects the amount of pollution in the air there. She found that the denser a town is, the more polluted it will be. This is an example of what type of relationship?
DIRECT!
We will extrapolate from this data

24. What type of relationship is this?
A student plotted the average monthly temperature for 36 months (3 years) straight. He noticed that during the summer months, the temperature was always hotter than during the winter months. This is an example of what type of relationship?
CYCLIC!

25. What type of relationship is this?
A student wanted to see if a sample of marble would change mass over time. He weighed the sample once every week for 3 months. He discovered that the mass of the rock did not change over his period of study. This is an example of what type of relationship?
STATIC!

26. Its safe to assume that whatever relationship we see on a graph will continue for the data points that are not on there – how you extrapolate
What is the relationship between relief (or slope) and the average rate of erosion?
As relief increases, the average rate of erosion increases --- DIRECT RELATIONSHIP