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4024/21 Oct/Nov 2025, Question 4: Scatter Diagrams and Correlation

Cambridge O Level Mathematics 4024 · Paper 21 (Calculator) · Calculator · 4 marks

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The question, in short

Table gives mathematics and physics marks for 9 students. Complete a scatter diagram, draw a line of best fit, and use it to estimate a mathematics mark for a physics mark of 75.

Summarised in our own words. Use the official paper for the exact wording and the diagram.

Part (a) · 2 marks

Plot the remaining 3 points from the table on the scatter diagram; the first 6 are already plotted.

  1. 1Plot the last three points: (60, 55), (45, 37), (78, 71)

AnswerThree points plotted correctly

Part (b) · 1 mark

Draw a line of best fit on the scatter diagram grid.

  1. 1Draw a ruled straight line with positive gradient through the middle of the points
  2. 2It should pass close to the mean point (59.3, 51.8)

AnswerRuled line of best fit

Part (c) · 1 mark

Xavier scored 75 in physics; use your line of best fit to estimate his mathematics mark.

  1. 1Go across from 75 on the Physics axis to the line, then down to the Mathematics axis
  2. 2Estimate ≈ 78 (your value depends on your line)

Answer78 (accept 75 to 82)

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