The temperature of water ( $w∘Cw^\circ\text{C}$ ) in a kettle $t\,$ minutes after it was boiled is recorded in the table below


$t$	2	4	7	10	13	16	21
$w$	84	73	61	51	43	36	26

The data is coded using the changes of variable $x = t$ and $y = \log_{10} w$

The regression line of $y\,$ on $x\,$ is found to be $y = 1.97 - 0.026 x$

Given that the data can be modelled by an equation in the form $w = ab^t$ where $a\,$ and $b\,$ are constants. Find the values of $a\,$ and $b\,$ to 3 significant figures.

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

Explain why this model is not reliable for calculating the temperature after 1 hour.

The temperature of water ( $w∘Cw^\circ\text{C}$ ) in a kettle $t\,$ minutes after it was boiled is recorded in the table below


$t$	2	4	7	10	13	16	21
$w$	84	73	61	51	43	36	26

The data is coded using the changes of variable $x = t$ and $y = \log_{10} w$

The regression line of $y\,$ on $x\,$ is found to be $y = 1.97 - 0.026 x$

Given that the data can be modelled by an equation in the form $w = ab^t$ where $a\,$ and $b\,$ are constants. Find the values of $a\,$ and $b\,$ to 3 significant figures.

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

Explain why this model is not reliable for calculating the temperature after 1 hour.

Regression, Correlation and Hypothesis Testing

Question 2

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Regression, Correlation and Hypothesis Testing

Question 2

Markscheme

Regression, Correlation and Hypothesis Testing

Question 2

Regression, Correlation and Hypothesis Testing Questions

Regression, Correlation and Hypothesis Testing

Question 2

Regression, Correlation and Hypothesis Testing Questions