Pictorial Representation of Data: Bar Chart and Line Graph - JSS1 Mathematics Lesson Note

Bar Chart:

A bar chart is a graphical representation of data where the length of bars represents the frequency or quantity of the data. It's commonly used to compare categories of data. Each bar typically corresponds to a category, and the height (or length) of the bar indicates the value it represents. For example, let's say we have data on the sales of fruits in a week:

Apples: 50 units

Oranges: 30 units

Bananas: 40 units

A bar chart would have three bars, one for each fruit, with heights of 50, 30, and 40 units respectively, representing their sales.

Line Graph:

A line graph uses points connected by lines to show how something changes over time or other continuous intervals. It's useful for displaying trends or relationships between variables. For instance, if we have data on the temperature over a week:

Monday: 20°C

Tuesday: 22°C

Wednesday: 25°C

Thursday: 24°C

Friday: 23°C

A line graph would plot these points on a graph where the x-axis represents the days of the week and the y-axis represents the temperature. Points are connected to show the trend in temperature change over the days.