# Exam-Style Question on Correlation

## A mathematics exam-style question with a worked solution that can be revealed gradually

##### List Of QuestionsExam-Style QuestionMore Correlation QuestionsMore on this Topic

Question id: 362. This question is similar to one that appeared on an IB Standard paper in 2018. The use of a calculator is allowed.

The following table shows the mean weight in kilograms of members of a group of young children of various ages.

 Age (x years) Weight ( y kg) 1.6 2.5 3.3 4.4 5.6 12 15 16 17 20

The relationship between the variables is modelled by the regression line with equation $$y = ax + b$$

(a) Find the value of $$a$$ and of $$b$$

(b) Write down the correlation coefficient.

(c) Use your equation to estimate the mean weight of a child that is four years old.

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