Histograms vs Bar Charts
Ever wondered why some graphs look similar but work completely differently? Bar charts use the height of bars to show frequency and work with discrete data (like shoe sizes or favourite colours). Histograms are trickier - they use the area of bars to show frequency and handle continuous data (like heights or times).
The key formula you absolutely must remember is: Frequency = Frequency density × Class width. This means the height of each bar (frequency density) multiplied by its width gives you the actual frequency. It's like calculating the area of a rectangle!
When drawing histograms, accuracy matters loads. Use a ruler, label your axes clearly, and remember there are no gaps between bars (unlike bar charts). Don't rush your frequency density calculations - show your working step by step.
Top Tip: Always double-check your frequency density calculations before drawing. One small error can mess up your entire histogram!
