1. 1 Press Ctrl-A ©G Dear 2008 – Not to be sold/Free to use Relative Error Stage 6 - Year 11 General Mathematics Preliminary

2. 2 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 cm Lower Limit = 167- 0.5= 166.5 cm

3. 3 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 kg Lower Limit = 77.6- 0.05= 77.55 kg

4. 4 Relative Error – Example 3/4 Find Bill’s BMI. Between what values will it lie? in kilograms in meters Weight Height 2 BMI = = 76.6 1.67 2 = 27.5 Normal = 20 - 25 Overweight = 26 - 29 Obese = 30

5. 5 Relative Error – Example 4/4 Find Bill’s BMI. Between what values will it lie? Weight Height 2 BMI = = 76.65 1.675 2 = 27.3 Using Upper-limit Weight Height 2 BMI = = 76.55 1.665 2 = 27.6 Using Lower-limit BMI = 27.45