MATHS - Statistics - Bar Graphs

I want to investigate how population has changed in these cities…but these numbers are just numbers. They don’t mean anything to me. In this video, we are going to discover how great bar graphs are for providing us with a clear visual, which is easy to read and interpret. Looking at this bar graph. We can now easily compare the populations of these cities in 2016… it clearly shows us that London is about one quarter the size of Tokyo. Or we could even have all 3 years on one bar graph, and compare the changes... We can easily see that some cities only have a small population change... Whereas other cities like Shanghai have a much larger change. Bar graphs are used to compare the amounts or frequencies of different things. So, for comparing different populations… Or frequencies... The taller the bar, the higher the frequency. Heart disease and cancer clearly cause many more deaths than everything else does. A bar graph should always have a title that makes it clear what is being shown. And labels on the axis. Most important are the bars. And there is a gap between each bar… most bar graphs have this gap because the data is discrete - you are either in one group or in another group. There are some special bar graphs where the bars do touch, called histograms, which we will look at in another video. There we have bar graphs. They are useful for comparing sets of data between different groups at a quick glance. The longer the bar, the greater its value. And they can run vertically or horizontally. Either one. Watch our video on pie charts to see an alternative method for displaying and comparing data.