Graphing Makes our life simpler! Why do we use graphs? It’s an organized way to express data...
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Transcript of Graphing Makes our life simpler! Why do we use graphs? It’s an organized way to express data...
Why do we use graphs?Why do we use graphs?
It’s an organized way to express data
Allows for easy interpretation of the data
What are the parts of a graph?What are the parts of a graph?
Independent variable:Independent variable:– Goes on Goes on “x”“x” ( (horizontalhorizontal) axis) axis– Controlled by the experimenterControlled by the experimenter
Dependent variable:Dependent variable:– Goes on Goes on “y”“y” ( (verticalvertical) axis) axis– Result of applying the independent variableResult of applying the independent variable
Let’s do a practice problem!Let’s do a practice problem!
Determining variablesDetermining variablesThe table shows data collected on the pH of a lake in the Adirondacks over 16 years.
Based on the table, what is the independent variable and what is the dependent variable?– ANS: IND = yearANS: IND = year
DEP = pH levelDEP = pH level
Setting up your graphSetting up your graphNow we know the variables, so we know where to plot them
– On X axis (independent)• Year
– On Y axis (dependent)• pH pHp
HYearYear
Interpreting your graphInterpreting your graph
What is the What is the trendtrend in pH of this lake over 16 in pH of this lake over 16 years?years?
– pH decreasespH decreases
– pH becomes more acidicpH becomes more acidic
What environmental condition(s) could’ve What environmental condition(s) could’ve caused this trend?caused this trend?
– Burning fossil fuelsBurning fossil fuels
– More factories in the areaMore factories in the area
– More industrializedMore industrialized
– More carsMore cars
Types of relationships determined Types of relationships determined by graphsby graphs
Direct relationship– BOTH variables INCREASE– Can you sketch a graph that shows this?
Types of relationships determined Types of relationships determined by graphsby graphs
Indirect relationship:– Independent variable increases, dependent
decreases– Can you sketch a graph with this relationship?
Types of relationships determined Types of relationships determined by graphsby graphs
Cyclic relationship:Cyclic relationship:– Shows repeating of same event over timeShows repeating of same event over time– Can you sketch a graph that shows a cyclic Can you sketch a graph that shows a cyclic
relationship?relationship?
Time
Types of relationships determined Types of relationships determined by graphsby graphs
Stable (no change):– Dependent variable stays the same as
independent increases– Can you sketch a graph showing stability?
Comparing rates of change using Comparing rates of change using graphsgraphs
The The angleangle of plotted line tells us the rate of plotted line tells us the rate– The STEEPER the line, the FASTER the rateThe STEEPER the line, the FASTER the rate– Which of the following graphs has a faster rate?Which of the following graphs has a faster rate?