Many real-life scenarios can be represented with line graphs.

Example 2

Match each scenario with the correct line graph.

  1. a non-stop 200 km journey at a constant speed

  2. the population growth of a bacteria colony

  3. the temperature of boiled water after it is removed from its heat source

  4. the amount of water in a pool as it drains

Scenario c.

Reason: As boiling water is removed from its heat source, its temperature will rapidly drop from 100°C. As the water cools and approaches room temperature, the rate of cooling will decrease.

Scenario a.

Reason: As time passes, there is a continuous and constant increase in distance for the 200 km journey.

Scenario b.

Reason: The population growth begins slowly, but as more and more bacteria are produced, the number available for reproduction increases, which results in a higher growth rate.

Scenario d.

Reason: The amount of water in the pool will decrease at a constant rate until the pool is empty.


When data values are nowhere near zero, breaks in the axes can be used to shorten the unnecessary portions of the axes between the origin and the first data value.

For the Exam Results Versus Study Time graph, there is no time data below 30 minutes and no percentage data below 45%. The indicated symbols in the graph above are called axis breaks. They are sometimes used to exclude unnecessary parts of a graph.