A researcher has grouped 240 waiting times using intervals of widths 2, 3, 5 and 10 minutes. The corresponding frequencies are 24, 54, 90 and 72.
In this question you must show detailed reasoning.
Calculate the frequency densities.
Identify the modal class and explain why comparing frequencies alone could give the wrong modal class for a histogram.
State one limitation of using the histogram to estimate how many waits were below a value inside a class.
8 exam-style questions on OCR A Level Maths 2.2.2 Area in a histogram. Each one has a worked solution and a mark scheme showing where the marks go.