A made-up shop records the rainfall and the umbrellas it sells on eight days…

Step 1. The means. $\bar{x} = \dfrac{87}{8} = 10.875\ \text{mm}$ and $\bar{y} = \dfrac{63}{8} = 7.875$ umbrellas.

Step 2. The lower left. The days with $0$, $2$, $5$ and $8$ mm have sales of $3$, $2$, $6$ and $5$, all below $7.875$. That is $4$ days.

Step 3. The upper right. The days with $12$, $15$, $20$ and $25$ mm sold $9$, $12$, $11$ and $15$, all above the mean. That is $4$ more days.

What it means. Every product $(x - \bar{x})(y - \bar{y})$ is positive, so $r$ is positive, and fairly large. In fact $r = 0.958$.