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Year 11 Maths — Statistics of grouped data

Find the mean, median and mode of grouped data, and read a cumulative frequency curve.

Name: ________________________

  1. 1.Match each class to its class mark.

    • 0–10
    • 20–40
    • 25–45
    • 50–70
    • 30
    • 5
    • 35
    • 60

  2. 2.A grouped table has the classes 0–10, 10–20, 20–30 and 30–40 with frequencies 2, 4, 3 and 1. Which class has the highest frequency? Give its lower limit.

  3. 3.What is the class mark — the midpoint — of the class 10–20?

  4. 4.What is the class mark of the class 40–70?

  5. 5.A grouped table has the classes 0–10, 10–20, 20–30 and 30–40 with frequencies 2, 4, 3 and 1. What is the total frequency?

  6. 6.In a grouped table the modal class is 30–40 with a frequency of 20. The class before it has a frequency of 10 and the class after it has a frequency of 5, and every class is 10 wide. The mode is l + ((f₁ - f₀) ÷ (2f₁ - f₀ - f₂)) × h. What is the mode?

  7. 7.This histogram shows a grouped frequency table. Tap the modal class.

    Write the number of the part.

    1234

  8. 8.A grouped table has the classes 0–10, 10–20, 20–30 and 30–40 with frequencies 2, 4, 3 and 1. What is the mean, using class marks?

Answer key — Year 11 Maths — Statistics of grouped data

  1. 1. 0–10 → 5; 20–40 → 30; 25–45 → 35; 50–70 → 60
  2. 2. 10
  3. 3. 15
  4. 4. 55
  5. 5. 10
  6. 6. 34
  7. 7. 2 — 10–20
  8. 8. 18