A bank reviews its customer records at the end of each month to find out how many customers have become unemployed, $u$, and how many have had their house repossessed, $h$, during that month - Edexcel - A-Level Maths Statistics - Question 2 - 2012 - Paper 2

To compute the product moment correlation coefficient, we use the formula:

$r = \frac{n(\sum xy) - (\sum x)(\sum y)}{\sqrt{[n \sum x^2 - (\sum x)^2][n \sum y^2 - (\sum y)^2]}}$

1. First, determine $n = 12$ (the number of months).
2. Calculate $\sum xy$ using the transformation:
   • Since $y$ is derived from $h$, we can backtrack to calculate $h$. Using the values in the summary, we can derive values for $x$ and $y$.
3. Substitute the computed values into the formula and simplify to find $r$.
4. The final result is:
   • $r \approx 0.818$.