Line Graphs

Line Graphs show continuous data. Examples include the world population, the value of the dollar, average daily temperatures, a patient's temperatures, and distances travelled on a journey.

Of the two variables in bar graphs, the independent variable is the one on which the other variable depends. The independent variable goes on the horizontal axis and a common example is the months of the year.

The dependent variable is written on the vertical axis and a common example includes the frequency.

Some important tips are:

Example - Computing Power

Moore's Law of Computing Power states that the number of components in integrated circuits (associated with processing speed, memory capacity, and the number of pixels in cameras) doubles every 2 years.

20101 000 gigabytes
20122 000 gigabytes
20144 000 gigabytes
20168 000 gigabytes
201816 000 gigabytes
202032 000 gigabytes


Moores Law diagram

Did You Know That...?

The world population in 2011 passed the 7 billion mark. That's you, me and 6 999 999 998 other humans - all breathing the same air and needing the same nutrients on our planet with its finite resources.

20006.115 billion
20106.909 billion
20207.675 billion
20308.309 billion
20408.807 billion
20509.150 billion


Draw a line graph of the world population using the estimated data in the table above. Extend that table till the year that you believe you will be a grandparent. How many others will be on Planet Earth then?