Answer
$y^{a}$
Work Step by Step
Comparing some powers with the same exponent (greater than 1), but with different bases
$a=3:\quad 2^{3}=8,\quad 3^{3}=27,\quad 10^{3}=1,000$,
$a=4:\quad 2^{4}=16,\quad 3^{4}=81,\quad 10^{4}=10,000$,
we observe a pattern in which
$x^{a} \lt y^{a}$, when $x \lt y \ $ and $\ a\gt 1$
Here, $y$ is the greater base, so $y^{a}$ is the greater power.