A biochemist monitors the relationship between the concentration of a specific catalyst, ccc mmol/L, and the resulting reaction rate, rrr μ\muμmol/s, for 10 distinct chemical trials. The experimental results are summarized as follows:
∑c2=9625∑cr=6792.5∑c=275∑r=220Srr=325 \sum c^2 = 9625 \quad \sum cr = 6792.5 \quad \sum c = 275 \quad \sum r = 220 \quad S_{rr} = 325 ∑c2=9625∑cr=6792.5∑c=275∑r=220Srr=325Determine the values of SccS_{cc}Scc and ScrS_{cr}Scr for this experiment.
Calculate, to 3 significant figures, the product moment correlation coefficient (PMCC) between ccc and rrr.
Find the equation of the least squares regression line of rrr on ccc in the form r=a+bcr = a + bcr=a+bc.
Identify which of the two variables is the explanatory variable in this study, providing a reason for your choice.
Using your regression model, estimate: (i) the reaction rate when the concentration of the catalyst is 32 mmol/L, (ii) the total change in the reaction rate for an 8 mmol/L increase in concentration.
It was later found that one trial, where the concentration was 20 mmol/L and the reaction rate was 25 μ\muμmol/s, was incorrectly transcribed and is considered an outlier.
State, with a reason, the effect that removing this outlier would have on the value of the PMCC.
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.