Exam-Style Question on Correlation
A mathematics exam-style question with a worked solution that can be revealed gradually
Question id: 12. This question is similar to one that appeared on an IB Studies paper in 2013. The use of a calculator is allowed.
In a survey of insect life near a stream, a student collected data about the number of different insect species \((y)\) that were found at different distances \((x)\) in metres from the stream.
|Insect species \((y)\)||26||25||19||19||14||9||5||3||2|
(a) Draw a scatter diagram to show the data.
(b) Using your scatter diagram, describe the correlation between the number of different insect species and the distance from the stream.
(c) Find \(\bar x\), the mean of the distances from the stream;
(d) Find \(\bar y\), the mean number of insect species.
(e) Plot the point \((\bar x,\bar y)\) on your scatter diagram. Label this point M.
(f) Write down the equation of the regression line \(y\) on \(x\) for the above data.
(g) Draw the regression line \(y\) on \(x\) on your scatter diagram.
(h) Estimate the number of insect species to be found 30 metres from the stream.
The worked solutions to these exam-style questions are only available to those who have a Transum Subscription.
Subscribers can drag down the panel to reveal the solution line by line. This is a very helpful strategy for the student who does not know how to do the question but given a clue, a peep at the beginnings of a method, they may be able to make progress themselves.
This could be a great resource for a teacher using a projector or for a parent helping their child work through the solution to this question. The worked solutions also contain screen shots (where needed) of the step by step calculator procedures.
A subscription also opens up the answers to all of the other online exercises, puzzles and lesson starters on Transum Mathematics and provides an ad-free browsing experience.
Drag this panel down to reveal the solution
©1997 - 2020 Transum Mathematics :: For more exam-style questions and worked solutions go to Transum.org/Maths/Exam/