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2.2 L: Data presentation and interpretation

2.2 L: Data presentation and interpretation

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Question 8

The number of bacteria, NNN, in a colony is recorded t t\,t hours after an experiment begins.

The data are coded using the changes of variable x=tx = tx=t and y=log⁡10Ny = \log_{10} Ny=log10​N.

The regression line of y y\,y on x x\,x is found to be

y=2.10+0.18xy = 2.10 + 0.18xy=2.10+0.18x

a.

Given that the data can be modelled by an equation of the form N=abtN = ab^{t}N=abt, where a a\,a and b b\,b are constants, find the value of a a\,a and the value of bbb. Give your answers to 3 significant figures.

[3]
b.

Give an interpretation of the constant a a\,a in this model.

[1]
c.

Explain why this model is unlikely to be reliable for predicting the number of bacteria one week after the experiment begins.

[1]
Markscheme

2.2 L: Data presentation and interpretation Questions

  1. A Level
  2. /Maths
  3. /2.2 L: Data presentation and interpretation

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.

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