Answer
12 light-years.
Work Step by Step
Use the angle to calculate the distance in parsecs. The relationship is given on page 958. The distance D is measured in parsecs, and the angle $\phi$ is measured in seconds of arc.
$$D=\frac{1}{\phi}=\frac{1}{0.27}=3.704\;pc$$
Convert to light-years.
$$(3.704pc)\frac{3.26ly}{1pc}=12\;ly$$
