Diagrams, charts and graphs

3.4.1 Try some yourself

Activity 22

Write down the coordinates of the point P on each of the graphs below and interpret these coordinates in terms of the labels on the axes.

Graph (a)
Graph (b)
Graph (c)

Answer

  • (a) (12.00, 30). This means that the temperature at midday was 30°C.

  • (b) (9.5, 10). At 9.30 a.m. the temperature was 10°C.

  • (c) (24, −60). On the 24th of the month there was −£60 in the bank (that is, the account was overdrawn by £60).

Activity 23

Choose the most suitable axes and plot the following sets of points:

  • (a) (2, 10), (4, 38), (7, 26), (5, 23);

Active content not displayed. This content requires JavaScript to be enabled, and a recent version of Flash Player to be installed.
  • (b) (350, 150), (420, 168), (630, 172), (570, 159);

Active content not displayed. This content requires JavaScript to be enabled, and a recent version of Flash Player to be installed.
  • (c) (140, 6), (−100, 30), (60, 13), (−60, 22).

Active content not displayed. This content requires JavaScript to be enabled, and a recent version of Flash Player to be installed.

Activity 24

Summarise the information given by the graph below.

Answer

The cost of coffee increased over the period from £5 per kilogram to over £10 per kilogram. It remained more or less steady between February and April, rose significantly during the month of April, then increased slowly but steadily until July.

Activity 25

Draw a graph on graph paper based on the data in this table. What shape is your graph?

Click on the link below for a graph paper PDF to print and use.

Graph Paper

Length of bus journey/km 0.5 1 1.5 2 2.5 3 3.5 4
Cost/£ 1.20 1.28 1.32 1.42 1.50 1.62 1.69 1.86

Answer

Again, the size of the graph paper and the scales used will have an effect, but your graph should resemble the one below. The graph is approximately a straight line.