The variables $x\,$ and $y\,$ are recorded for 12 items, and the product moment correlation coefficient between $x\,$ and $y\,$ is -0.47.

The data are then coded using the changes of variable $m = \log_{10} x$ and $n = \log_{10} y$ . The product moment correlation coefficient between $m\,$ and $n\,$ is -0.83, and the regression line of $n\,$ on $m\,$ is

$n = 0.25 - 0.16 m$

Explain how these two correlation coefficients support the use of a model of the form $y = ax^{b}$ rather than a linear model in $x\,$ and $y$ .

Show that the relationship between $x\,$ and $y\,$ can be written in the form $y = ax^{b}$ , and find the value of $a\,$ to 3 significant figures and the value of $b$ .

The variables $x\,$ and $y\,$ are recorded for 12 items, and the product moment correlation coefficient between $x\,$ and $y\,$ is -0.47.

$n = 0.25 - 0.16 m$

Explain how these two correlation coefficients support the use of a model of the form $y = ax^{b}$ rather than a linear model in $x\,$ and $y$ .

Show that the relationship between $x\,$ and $y\,$ can be written in the form $y = ax^{b}$ , and find the value of $a\,$ to 3 significant figures and the value of $b$ .

2 Statistics

Question 216

Markscheme

2 Statistics

Question 216

Markscheme

2 Statistics

Question 216

2 Statistics Questions

2 Statistics

Question 216

2 Statistics Questions