Consider grouped data that have been recorded in the following way: 20–29, 30–39, 40–49, and so on.
Answer the questions that follow.
(i) Define the terms (a) inclusive class interval and (b) continuous class interval.
(ii) Explain, with two clear reasons, why class intervals must be written in a continuous form before a histogram or an ogive is drawn.
(iii) Show how the class interval 20–29 is converted to its corresponding continuous class boundaries when the data values are whole numbers only.