The frequency density for 0<x≤4 0<x\leq4\,0<x≤4 is 6. The adjacent class 4<x≤10 4<x\leq10\,4<x≤10 has frequency 3k3k3k. The two histogram bars have equal area.
Find kkk.
Find the height ratio of the first bar to the second bar.
121 exam-style questions on OCR A Level Maths 2.2 Data Presentation and Interpretation, covering 2.2.1 Tables and diagrams for single variable data, 2.2.2 Area in a histogram, 2.2.3 Scatter diagrams and regression lines, 2.2.4 Informal interpretation of correlation, 2.2.5 Correlation and causation, 2.2.6 Measures of average and spread, 2.2.7 Calculations of mean and standard deviation, 2.2.8 Outliers, 2.2.9 Selecting or critiquing data presentation, and 2.2.10 Cleaning data. Each one has a worked solution and a mark scheme showing where the marks go.