The table below shows the number of active high-performance servers, $s$ , and the cooling energy consumption, $e$ kWh, in a data center over 8 separate observation periods.

$s$	5	12	15	20	25	30	35	42
$e$	12	18	25	32	40	45	55	61

You may use $S_{ss} = 1076$ and $S_{ee} = 2120$ .

Find the exact value of $∑se\sum se$ .

Find the value of $S_{se}$ .

Calculate the product moment correlation coefficient between $s$ and $e$ , giving your answer to 3 decimal places.

Interpret the value of the correlation coefficient in the context of the data center.

A ninth observation is added to the data set. On this day, 45 servers were active and the cooling energy consumption was 15 kWh.

Without further calculation, state whether the value of the product moment correlation coefficient will increase, decrease or stay the same when all nine observations are used. Give a reason for your answer.

The table below shows the number of active high-performance servers, $s$ , and the cooling energy consumption, $e$ kWh, in a data center over 8 separate observation periods.

$s$	5	12	15	20	25	30	35	42
$e$	12	18	25	32	40	45	55	61

You may use $S_{ss} = 1076$ and $S_{ee} = 2120$ .

Find the exact value of $∑se\sum se$ .

Find the value of $S_{se}$ .

Calculate the product moment correlation coefficient between $s$ and $e$ , giving your answer to 3 decimal places.

Interpret the value of the correlation coefficient in the context of the data center.

A ninth observation is added to the data set. On this day, 45 servers were active and the cooling energy consumption was 15 kWh.

2.2.2 Scatter diagrams and correlation

Question 54

Markscheme

2.2.2 Scatter diagrams and correlation

Question 54

Markscheme

2.2.2 Scatter diagrams and correlation

Question 54

2.2.2 Scatter diagrams and correlation Questions

2.2.2 Scatter diagrams and correlation

Question 54

2.2.2 Scatter diagrams and correlation Questions