1. How to Understand Graphs Source

2. How to Understand Graphs A graph is a two-dimensional representation of a set of numbers, or data. Time Series Graph A time series graph shows how a single variable changes over time.

3. How to Read and Understand Graphs Time Series Graph Total Disposable Personal Income 1975–2006

4. Plotting Income and Consumption Data for Households Consumption Expenditures and Income,2005 £bn Average Income Before Taxes Average Consumption Expenditures

5.  A positive slope indicates that increases in X are associated with increases in Y and that decreases in X are associated with decreases in Y. A Curve with (a) Positive Slope and (b) Negative Slope A negative slope indicates the opposite—when X increases, Y decreases and when X decreases, Y increases. How to Read and Understand Graphs

6. Changing Slopes Along Curves How to Read and Understand Graphs

7. Some Precautions Aggregate National Income and 1930–2006 (£bn)

8. Key Terms • graph • negative relationship • origin • positive relationship • slope • time series graph • X-axis • Y-axis