From the 3 options listed, both \(5.25\) in and \(6.5\) in could be measures found using a ruler with eighth inches marked, because those decimals can be written in terms of eighth fractions.
\(5.25 $in $ \rightarrow (5 + 0.25) $in $ \rightarrow (5 + \frac{2}{8} ) $in$ \\
6.5 $in $ \rightarrow (6 + 0.5) $in $ \rightarrow (5 + \frac{4}{8} ) $in$\)
The other option, \(7.1\) in, is not a possibility because 0.1 cannot be written as a fraction of 8 that is marked on the ruler.
