1. 4-Mar-16 Starter Questions Starter Questions

2. 4-Mar-16 Ratio & Proportion The table below shows the cost of packets of “Biscuits”. Direct Proportion Graphs We can construct a graph to represent this data. What type of graph do we expect ?

3. 4-Mar-16Created by Mr. Lafferty Maths Dept. Direct Proportion Graphs Notice that the points lie on a straight line passing through the origin This is true for any two quantities which are in Direct Proportion.

4. 4-Mar-16 Ratio & Proportion Direct Proportion Graphs KeyPoint Two quantities which are in DIRECT PROPORTION always lie on a straight line passing through the origin.

5. 4-Mar-16 Ratio & Proportion Example : Plot the points in the table below. Are they in direct proportion? Direct Proportion Graphs We plot the points (1,3), (2,6), (3,19), (4,12)X1234y36912

6. 4-Mar-16 1 Ratio & Proportion Plotting the points (1,3), (2,6), (3,9), (4,12) Direct Proportion Graphs 01234 10 11 12 2 3 4 5 6 7 8 9 Since we have a straight line passing through the origin x and y are in direct proportion. x y