Mathematics 4024 · O Level · Statistical charts and diagrams

Statistical charts and diagrams — practice question

Sunil noted the call lengths, in minutes, for the 150 phone calls he made during one month. These results are shown in the table.

(a)[3]

Calculate an estimate of the mean length of a call.

(b)[3]

On the grid provided, draw a histogram to show this data.

(c)[2]

Find an estimate for the percentage of Sunil’s calls that lasted longer than 25 minutes.

Worked solution & mark scheme

This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Correct use of the class midpoints” …