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4024/11 May/Jun 2020, Question 10: Scatter Diagrams and Correlation

Cambridge O Level Mathematics 4024 · Paper 11 (Non-calculator) · Non-calculator · 5 marks

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The question, in short

Complete a scatter diagram from a table of plant height against days, then describe the correlation, draw a line of best fit, and judge whether 100 days can be predicted.

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

Part (a) · 2 marks

Plot the remaining pairs of days and height on the grid to finish the scatter diagram.

  1. 1Plot the other five points: (51, 10.8), (62, 11.3), (68, 11.4), (73, 11.8), (80, 11.8)

Answer5 points plotted correctly

Part (b) · 1 mark

State the kind of correlation the scatter diagram shows.

  1. 1As the number of days increases, the height increases
  2. 2Positive correlation

Answerpositive

Part (c) · 1 mark

Add a line of best fit to the plotted points.

  1. 1Draw one ruled straight line through the middle of the points, from about (15, 8.6) to (80, 11.9)
  2. 2Roughly equal numbers of points above and below the line

AnswerRuled line of best fit drawn

Part (d) · 1 mark

Decide if the diagram predicts height at 100 days and justify your decision.

  1. 1No, because 100 days is outside the data: we do not have any data beyond 80 days

AnswerNo, because we do not have any data beyond 80 days

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