A biologist studying bacterial growth records the incubation time, ttt minutes, and the mass of nutrients consumed, mmm milligrams, for n=15n = 15n=15 separate samples. Each sample is initially provided with a petri dish containing 18.018.018.0 mg of nutrient. The summary statistics for these 151515 samples are as follows:
∑t=202.5,∑m=49.5,∑tm=745.2,Stt=1440.0,Smm=7.5 \sum t = 202.5, \quad \sum m = 49.5, \quad \sum tm = 745.2, \quad S_{tt} = 1440.0, \quad S_{mm} = 7.5 ∑t=202.5,∑m=49.5,∑tm=745.2,Stt=1440.0,Smm=7.5Calculate the product moment correlation coefficient between ttt and mmm.
The mass of nutrient remaining in the dish at the end of the incubation period is recorded as RRR milligrams. (i) Write down an equation for RRR in terms of mmm. (ii) State the value of the product moment correlation coefficient between RRR and mmm.
State the value of the product moment correlation coefficient between ttt and RRR.
244 exam-style questions on AQA A Level Maths 2.2 L: Data presentation and interpretation, covering 2.2.1 Single-variable data diagrams, 2.2.2 Scatter diagrams and correlation, 2.2.3 Central tendency, variation and standard deviation, 2.2.4 Outliers and cleaning data, and 2.2 L: Data presentation and interpretation. Each one has a worked solution and a mark scheme showing where the marks go.