A student draws a histogram for two classes, 0≤x<5 0\leq x<5\,0≤x<5 with frequency 20 and 5≤x<15 5\leq x<15\,5≤x<15 with frequency 30. The student uses bar heights 20 and 30.
Explain why these heights give a misleading histogram.
Calculate the two correct frequency densities.
8 exam-style questions on OCR (MEI) A Level Maths 2.2.2 Area in a histogram is proportional to frequency. Each one has a worked solution and a mark scheme showing where the marks go.