Reading & Understanding Graphs

Parts of a Graph Title: ____________________________ Independent Variable Dependent Variable & Units of Measurement X-axis Y-axis

Interpreting Graphs Examine each graph carefully. X-axis –What was tested, changed, or compared –Independent Variable Y-Axis –The data that was observed and measured –Dependent Variable

Identify the Variables Example #1

Example #1 Title: –Effect of fertilizer on plant height Independent Variable: –Type of fertilizer Dependent Variable: –Average plant height (cm)

Example #1 Controlled Variables: –Same amount of light, fertilizer, and water. What is the graph saying? –The type of fertilizer influences the plant height. –SuperGro had the greatest effect. –NoGrow had the least effect on plant height.

Example #2

Title: –Popular Bachelor’s Degrees Independent Variable: –Discipline Division (type of degree) Dependent Variable: –Number of degrees awarded

Example #2 Controlled Variables: –Degrees are categorized the same way. What is the graph saying? –Business was the most popular bachelor’s degree and engineering was the least.

Example #3

Title: –Relationship between time spent studying and test grades Independent Variable: –Time spent studying (min) Dependent Variable: –Grades on test

Example #3 Controlled Variables: –Similar ability students, same test What is the relationship between the variables? –As the time spent studying increases, the grades on tests increases.

Example #4

Title: –U.S. Public School Student Membership Independent Variable: –Year Dependent Variable: –Student membership (in millions)

Example #4 Controlled Variables: –All schools report. Students not counted twice. What is the relationship between the variables? –As the year increases, the student membership in U.S. public schools increases.

Example #5

Title: –Relationship between missed free throws and wins Independent Variable: –Number of missed free throws per game Dependent Variable: –Number of wins

Example #5 Controlled Variables: –Same team, no overtime What is the relationship between the variables? –As the number of missed free throws per game increases, the number of wins decreases.