Use Fig. 30–11 and calculate the relative decay rates for $\alpha$ decay of ${^{218}_{84}\textrm{Po}}$ and ${^{214}_{84}\textrm{Po}}$.

Figure 30-11 Decay series beginning with $^{238}_{92}\textrm{U}$. Nuclei in the series are specified by a dot representing $A$ and $Z$ values. Half-lives are given in seconds (s), minutes (min), hours (h), days (d), or years (yr). Note that a horizontal arrow represents $\beta$ decay ($A$ does not change), whereas a diagonal line represents $\alpha$ decay ($A$ changes by 4, $Z$ changes by 2). For the four nuclides shown that can decay by both $\alpha$ and $\beta$ decay, the more prominent decay (in these four cases, >99.9%) is shown as a solid arrow and the less common decay (<0.1%) as a dashed arrow.