How to apply the Geiger–Nuttall rule to find half-life?

I'm having trouble understanding the Geiger–Nuttall rule for α-particle decay. From the textbook I'm using, the rule is defined as


$$
\log(t\_{1/2}) = A + \frac{B}{\sqrt{Q\_\alpha}},
$$


where the constants $A$ and $B$ have a $Z$ dependence. Here's a Geiger–Nuttall plot of the logarithm of the half-life (s) versus the square root of the $Q\_α$ value (MeV):


[![Geiger– Nuttall plot](https://i.stack.imgur.com/J0NTf.png)](https://i.stack.imgur.com/J0NTf.png)


How do we use the above equation to find the half-life? More specifically, can we use that to find the half-life of $\ce{^{226}Ra}$ nuclei?


