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4.3.1 Statistical hypothesis testing (A-level only)

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Question 77

A biochemist is studying the effect of temperature, TTT in ∘C^\circ\text{C}∘C, on the rate of a catalytic reaction, VVV in units of 10−2 mol s−110^{-2} \text{ mol s}^{-1}10−2 mol s−1. Data from a random sample of 12 experiments are summarised as follows:

∑T=480∑T2=21200∑V=150∑V2=2025 \sum T = 480 \quad \sum T^2 = 21200 \quad \sum V = 150 \quad \sum V^2 = 2025 ∑T=480∑T2=21200∑V=150∑V2=2025

and the regression line of VVV on TTT has the equation V=2.5+0.25TV = 2.5 + 0.25TV=2.5+0.25T.

a.

Use the regression line to estimate the rate of reaction in mol s−1\text{mol s}^{-1}mol s−1 for an experiment conducted at 35∘C35^\circ\text{C}35∘C.

[2]
b.

Find the values of STTS_{TT}STT​ and SVVS_{VV}SVV​.

[2]
c.

Calculate the product moment correlation coefficient between TTT and VVV.

[3]
d.

A 13th experiment is performed. The temperature is recorded as 40∘C40^\circ\text{C}40∘C and the rate of reaction is measured as 0.125 mol s−10.125 \text{ mol s}^{-1}0.125 mol s−1.

Use the formula STV=∑(T−Tˉ)(V−Vˉ)S_{TV} = \sum (T - \bar{T})(V - \bar{V})STV​=∑(T−Tˉ)(V−Vˉ) to demonstrate that the value of STVS_{TV}STV​ for the 13 experiments will be identical to its value for the original 12 experiments.

[3]
e.

Determine the new equation of the regression line of VVV on TTT for the full set of 13 experiments.

[2]
f.

Comment on the reliability of using the new regression line to estimate the rate of reaction for an experiment conducted at 120∘C120^\circ\text{C}120∘C, providing a justification for your answer.

[2]

4.3.1 Statistical hypothesis testing (A-level only) Questions

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