AP Economics

Mr. Bernstein

Section 1 Appendix: Graphs in Economics

September 2015

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AP EconomicsMr. 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 EconomicsMr. 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 EconomicsMr. 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 EconomicsMr. Bernstein

Slope of a Linear Curve

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AP EconomicsMr. Bernstein

Nonlinear Curves• Positive Increasing Slope• Positive Decreasing Slope• Negative Increasing Slope (concave)• Negative Decreasing Slope (convex)

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AP EconomicsMr. Bernstein

Nonlinear Curves

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AP EconomicsMr. 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 EconomicsMr. 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 EconomicsMr. Bernstein

Graphs That Depict Numerical Information• Time-Series• Scatter Diagrams• Pie Charts• Bar Charts and Histograms