Draw a rough histogram for the distribution 0–10: 5, 10–20: 12, 20–30: 8, 30–40: 3, and mark the modal class.

The marks of 40 students are grouped into class intervals of width 10. Explain how the modal class is identified from a histogram of the data.

Why must class intervals be converted to their exclusive form before a histogram is drawn?

State two differences between a bar graph and a histogram.

What is an ogive, and what is read from the point where the two ogives of a distribution intersect?

A less-than ogive is drawn for 60 observations. Explain how the median, the lower quartile and the upper quartile are read from it.

Explain the term cumulative frequency and state how the cumulative frequency of a class is obtained.