In a histogram, the class 10≤x<18 10\leq x<18\,10≤x<18 has height 2.5 and represents 20 observations. The class 18≤x<30 18\leq x<30\,18≤x<30 represents 18 observations.
Explain why histogram area, rather than height, represents frequency.
Find the height of the second bar on the same frequency-density scale.
105 exam-style questions on WJEC A Level Maths 2.2 Data presentation and interpretation, covering 2.2.1 Data presentation and interpretation, 2.2.2 Data presentation and interpretation, 2.2.3 Data presentation and interpretation, 2.2.4 Data presentation and interpretation, 2.2.5 Data presentation and interpretation, 2.2.6 Data presentation and interpretation, 2.2.7 Data presentation and interpretation, 2.2.8 Data presentation and interpretation, and 2.2 Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.