Hi. I am a pretty confused right now, regarding the topic of Correlation Coefficients. My [Hodder maths textbook](https://media.discordapp.net/attach...cs-Year-2-textbook-E.png?width=291&height=375) explains how to find Spearman's rank correlation coefficient, and a product moment correlation coefficient (PMCC), also providing questions to find them. However I looked in my [CGP revision guide](https://encrypted-tbn3.gstatic.com/...ZnoyNosyLzhl5crTwgYoM0ud_WtQ_e_cAVH0&usqp=CAE) (both are for the new 2017 spec) says [this](https://scontent.fbhx2-1.fna.fbcdn....=4e7a1bbc59d17f8d5f1e90cf16a15b4d&oe=5D286830), 'you only need to interpret the values of r (not find it)' where r is the PMCC. So I looked in the [official AQA teaching guidance document](https://allaboutmaths.aqa.org.uk/attachments/9406.pdf) and it says [this](https://scontent.fbhx2-1.fna.fbcdn....=c6e15d955ab99c00c57bf7e5b2ada16d&oe=5D1332F7), 'students will NOT be required to calculate a correlation coefficient'. So, from that I would just think that I won't bother learning this, and the formulae for it is also not in the AQA formula booklet. But today in maths at school we were taught how to find Spearman's rank correlation coefficient. I am so confused, please, if anyone knows, do we need to know these topics for AQA, or not? Thanks.