CAIE IGCSE Mathematics Core Straight-Line Best Fit

Practise selecting or drawing a ruled line that represents a scatter trend and using the line with the diagram scale to estimate an unknown value.

Syllabus
2028–2030
Objective
C9.5.3
Level
Core

Exam points

  • draw one ruled line across the full data range with a roughly even spread of points on each side
  • reject candidate lines that miss the trend, cover too little of the data or leave an uneven balance
  • read across and down from a given coordinate to estimate the paired value from the fitted line

C9.5.3 Draw by eye, interpret and use a straight line of best fit question 1

[Maximum number: 2]

Question (a)

(a)

Ten students eat cereal with milk for breakfast.
The amounts are shown in the table.

Table for Question (a) — CAIE IGCSE Mathematics Core
Figure for Question (a) — CAIE IGCSE Mathematics Core
[ 2 ]

Question (i)

(i)

On the grid, draw a line of best fit.

[ 1 ]

Question (ii)

(ii)

Another student has 280 ml of milk with her cereal.

Use your line of best fit to estimate an amount of cereal this student has.

___ g

[ 1 ]
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