AP Economics
Mr. Bernstein
Section 1 Appendix: Graphs in
Economics
September 12, 2014
AP Economics
Mr. Bernstein
Plotting Points on a Two-Variable Graph
• Horizontal axis is X-axis
• Vertical axis is Y-axis
• Origin is where axes meet, variables = zero
• X-axis is the independent variable
• Y-axis is the dependent variable
• Example: Temperature and soda sales
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AP Economics
Mr. Bernstein
Curves on a Graph
• Linear Relationship
• Positive Relationship
• Negative Relationship
• Examples: Temperature and soda sold,
Temperature and Hot Chocolate sold
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AP Economics
Mr. Bernstein
Slope of a Linear Curve
• Measure of steepness, or how strong the
effect of the independent variable is on the
dependent variable…aka sensitivity or delta
• Change in y / Change in x = slope
• Slope of horizontal line is zero
• Slope of vertical line is infinite
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AP Economics
Mr. Bernstein
Slope of a Linear Curve
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AP Economics
Mr. Bernstein
Nonlinear Curves
• Positive Increasing Slope
• Positive Decreasing Slope
• Negative Increasing Slope (concave)
• Negative Decreasing Slope (convex)
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AP Economics
Mr. Bernstein
Nonlinear Curves
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AP Economics
Mr. Bernstein
Slope of Nonlinear Curves
• Slope is changing as you move along the curve
• Slope is typically expressed as the slope
between two points
• Curves can have maximum or minimum points
(where slope changes from positive to
negative or vice versa)
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AP Economics
Mr. Bernstein
Calculating Area Below or Above a Linear Curve
• Measure height and base of right triangle,
multiply, then divide by 2
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AP Economics
Mr. Bernstein
Graphs That Depict Numerical Information
• Time-Series
• Scatter Diagrams
• Pie Charts
• Bar Charts and Histograms
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