GCSE Maths Unit 1 - Two-way tables & Observation Sheets
February 2, 2016
GCSE Maths – Two-way Tables & Observation Sheets – Sample Question
Some boys and girls are asked if they can whistle. There are 30 boys(1) and there are three times as many girls as boys(2). 40% of the girls can whistle(3) and the ratio of boys that can whistle to girls that can whistle is 2:3(4).
i) Draw and complete a two-way table for this data.
ii) Why would this data not be suitable for investigating the incidence of the ability to whistle among the entire UK population?
36 x 2 ÷ 3 = 24 (4)
40% of 90 = 36 (3)
30 – 24 = 6
90-36 = 54
3 x 30 = 90 (2)
ii) The population as a whole contains adults as well as children (there are no adults included in this sample at all) and is roughly equally split between male and female (this group contains far more female than male, in the ratio 3:1). Thus this sample is not representative of the whole population.