0580/42 Feb/Mar 2024, Question 3: Histograms (Unequal Class Intervals)

Part (ai) · 1 mark

Calculate the range of the 10 marks from the frequency table.

1. 1Range = 20 − 15 = 5

Answer5

Part (aii) · 3 marks

Calculate the mean mark of the 10 students.

1. 1Σfx = 15×4 + 16×1 + 17×2 + 18×1 + 19×0 + 20×2
2. 2= 60 + 16 + 34 + 18 + 0 + 40 = 168
3. 3Mean = 168 ÷ 10 = 16.8

Answer16.8

Part (aiii) · 1 mark

Find the median mark of the 10 students.

1. 110 marks: median is between the 5th and 6th
2. 25th = 16, 6th = 17
3. 3Median = (16 + 17) ÷ 2 = 16.5

Answer16.5

Part (aiv) · 1 mark

Write down the mode of the marks.

1. 1Highest frequency is 4, for mark 15
2. 2Mode = 15

Answer15

Part (b) · 3 marks

Given Paulo's mean for 7 tasks is 17 and for 8 tasks is 17.5, calculate his 8th task mark.

1. 1Total for 8 tasks = 8 × 17.5 = 140
2. 2Total for 7 tasks = 7 × 17 = 119
3. 38th mark = 140 − 119 = 21

Answer21

Part (c) · 4 marks

Draw a histogram on the grid for the grouped percentage data of 100 students, using frequency density.

1. 1Frequency density = frequency ÷ class width
2. 20−30: 12 ÷ 30 = 0.4; 30−50: 18 ÷ 20 = 0.9; 50−60: 35 ÷ 10 = 3.5
3. 360−70: 20 ÷ 10 = 2; 70−100: 15 ÷ 30 = 0.5
4. 4Draw 5 touching bars with these widths and heights

Answer5 correct blocks, with correct widths, heights

More past-paper questions on histograms (unequal class intervals)

• 0580/21 May/Jun 2026 Q22 · 3 marks
• 0580/42 May/Jun 2026 Q19 · 7 marks
• 0580/42 Feb/Mar 2025 Q15 · 7 marks
• 0580/22 May/Jun 2025 Q13 · 11 marks
• 0580/41 May/Jun 2025 Q15 · 9 marks
• 0580/43 May/Jun 2025 Q24 · 4 marks