Mathematics 9709 · AS & A Level · Sampling and estimation
Sampling and estimation — practice question
Ronnie collected figures for the gross domestic product (GDP) and the birth rate of 170 countries. He put each GDP and each birth rate into low, medium or high groups. The table gives the number of countries in each group.
(i)[1]
Find the probability that the selected country has a medium GDP.
(ii)[2]
Find the probability that the selected country has a low birth rate, given that it does not have a medium GDP.
(iii)[2]
State, with a reason, whether the events ‘the country chosen has a high GDP’ and ‘the country chosen has a high birth rate’ are exclusive or not.
(iv)[3]
Find the probability that both selected countries have a medium GDP and a medium birth rate.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Correct probability $\frac{74}{170}=\frac{37}{85}=0.435$” …