1. Introduction to Macroeconomics Chapter 1 Appendix. Working with Numbers and Graphs

2. EconClass - Introduction to Macroeconomics Chapter 1 Appendix Working with Numbers and Graphs 1. Working with Numbers –Marginal Change and Analysis –Percentage Change –Elasticity 2. Working with Graphs –Graph Plotting Area –Graphing an Equation –Slopes –Nonlinear Relationships –Shifting and Rotating a Curve

3. EconClass - Introduction to Macroeconomics 1. Working with Numbers Percentage Change Percentage Change = (Ending Value - Starting Value) x 100 Starting Value

4. EconClass - Introduction to Macroeconomics 2. Working with Graphs Graph Plotting Area Positive Values of X and Y Origin: X = 0 and Y = 0

5. EconClass - Introduction to Macroeconomics 2. Working with Graphs Graphing an Equation Y = 10 + 0.75 * X Slope = change in Y (rise) = 0.75 change in X (run) Intercept = 10 = value of Y when X equals 0 “Run” “Rise”

6. EconClass - Introduction to Macroeconomics 2. Working with Graphs Slopes Positive Slope (slope > 0) X and Y are directly related Negative Slope (slope < 0) X and Y are inversely related Zero Slope (slope = 0)Undefined Slope (slope =  )

7. EconClass - Introduction to Macroeconomics 2. Working with Graphs Nonlinear Relationships Slope of Tanget (at X=4) = + 8.6 Positive Slope Slope becomes zero at maximum Negative Slope Study Time and Expected Grade

8. EconClass - Introduction to Macroeconomics 2. Working with Graphs Shifting a Curve Start: Y = 10 + 0.75 * X End: Y = 15 + 0.75 * X Increase in Intercept from 10 to 15

9. EconClass - Introduction to Macroeconomics 2. Working with Graphs Changing the Slope of a Curve Start: Y = 10 + 0.75 * X End: Y = 10 + 0.90 * X Increase in Slope from 0.75 to 0.90