If $\dfrac{a}{b} = \dfrac{c}{d} = \dfrac{e}{f} = \dfrac{g}{h} = k$, then $\dfrac{a+c+e+g}{b+d+f+h} =$

By the addendo (sum) rule, when all the equal ratios equal $k$, the ratio of the sum of numerators to the sum of denominators also equals $k$, not $4k$. Substituting $a=bk,\ c=dk,\dots$ gives .