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Relative ErrorRelative ErrorStage 6 - Year 11Stage 6 - Year 11

General MathematicsPreliminary

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Relative Error – Example 1/4

Bill’s height is 167 cm. Between what values will it lie?

The relative error is half of the smallest unit (1 cm). ie ± 0.5 cm

Upper Limit =

167 + 0.5 = 167.5 cmLower Limit

=167 - 0.5 = 166.5

cm

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Relative Error – Example 2/4

Bill’s weighs is 77.6 kg. Between what values will it lie?

The relative error is half of the smallest unit (0.1 kg). ie ± 0.05 kg

Upper Limit =

77.6+ 0.05

= 77.65 kgLower Limit =

77.6- 0.05 = 77.55 kg

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Relative Error – Example 3/4

Find Bill’s BMI. Between what values will it lie?

in kilogramsin meters

WeightHeight2

BMI ==76.6

1.672

= 27.5

Normal = 20 - 25Overweight = 26 - 29

Obese = 30

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Relative Error – Example 4/4

Find Bill’s BMI. Between what values will it lie?

WeightHeight2

BMI ==76.65

1.6752

= 27.3

Using Upper-limitWeightHeight2

BMI ==76.55

1.6652

= 27.6

Using Lower-limit

BMI = 27.45