I need to use which graph? Graphing I need to use which graph?

Types of Graphs We will use one of 3 kinds of graphs: line graph, pie graph, and bar graphs Line graphs are good a representing changes over time, when the data is continuous Bar graphs are used for comparison of quantities that are not fixed Pie graphs compare the parts of a whole Be sure to use the appropriate graph for the given data

Variables The independent variable goes on the X-axis (remember this is the variable that the experimenter chooses) The dependent (sometimes called responding) variable goes on the Y-axis (remember this happens as a result of the independent variable As a general rule, time should go on the X-axis

Special Cases (line graphs) Any straight line indicates that the 2 variables are in direct proportion (draw example on board) that is when the 2 variables are in a constant ratio A curved line could indicate a inverse proportion line graph where the product of the 2 variables is always equal Slope is difficult to measure on a curved line, so if we find slope we will do it on a straight line