Graphing

Choosing the Right Graph

A BAR GRAPH is best used for comparing data quickly and easily, such as the grade distribution of students enrolled in science class.

A PIE GRAPH is best used for showing percentages, such as the percentage of th student body who picked certain entrees for lunch.

A LINE GRAPH is best used for looking at changes over time, such as the number of bathing suits sold each month during the year.

CREATING GRAPHS

*First, set up your graphs with an x-axis and a y-axis. The x-axis is horizontal and the y-axis is verticle. The axes represent different variables in an experiment.
*The x-axis represents the independant variable. The independent variable is the variable whose values are chosen by the experimenter. For example, the range of grades is the independant variable.
*The y-axis represents the dependent variable. The values for the dependaent variable are determined by the independent variable. If you are grouping students by grades, the number of students in each group depends on the grade they get.
*Next, choose a scale for each of the axes. Select evenly spaced intervals that include all of your data. When you label the axes, be sure to write the appropriate units where they apply.
*Next, plot your data on the graph. Make sure you double-check your numbers to ensure accuracy.
*Finally, give your graph a title. A title tells the reader what he or she is studying. A good title should explain the relationship between the variables. Your graph is then complete.