A marine biologist measured the dissolved oxygen level, ddd mg/L, at various depths, hhh meters, in a specific estuary. Data from a random sample of 10 locations are summarized as follows:
∑h=155∑h2=2875∑d=62.4Sdd=18.2∑hd=884.2 \sum h = 155 \quad \sum h^2 = 2875 \quad \sum d = 62.4 \quad S_{dd} = 18.2 \quad \sum hd = 884.2 ∑h=155∑h2=2875∑d=62.4Sdd=18.2∑hd=884.2Calculate the values of ShhS_{hh}Shh and ShdS_{hd}Shd.
Calculate, to 3 significant figures, the product moment correlation coefficient between hhh and ddd.
The biologist also measured the water temperature, ttt °C, at the same 10 locations. The product moment correlation coefficient between hhh and ttt was found to be −0.915-0.915−0.915.
Describe, giving a reason, the nature of the correlation you would expect to find between temperature (ttt) and dissolved oxygen (ddd).
202 exam-style questions on Edexcel A Level Maths Regression, Correlation and Hypothesis Testing, covering 1.1 Exponential Models, 1.2 Measuring Correlation, and 1.3 Hypothesis Testing for Zero Correlation. Each one has a worked solution and a mark scheme showing where the marks go.