#### Answer

$\frac {1}{9}$

#### Work Step by Step

Keep in mind that the index is the denominator of the exponent.
To write an expression without a negative exponent, take the reciprocal of the base with the same exponent's absolute value.
$27^{-2/3}$
$\frac {1}{27^{2/3}}$ Reciprocal.
$\frac {1}{(\sqrt[3]{27})^{2}}$
$\frac {1}{(3)^{2}}$
$\frac {1}{9}$