A parent recently sent me some questions and I would like to share with you this one on Cumulative Frequency.

The tricky part of question (c) is **reading the scale** correctly.

- Every small square is 2 units on the x-axis
- Every small square is 4 units on the y-axis

For (ii), total number of students (160) represent the entire pie chart which is 360 degrees.

Therefore, by proportion, we can find out the degrees of the pie chart for students who are awarded C grade.