Log2y=1/3(log2 27power)
log2y = (1/3)log227
Since a multiplier goes into the log expression as an exponent:
log2y = log2271/3
An exponent of 1/3 represents a cube root, so 271/3 = 3 (the cube root fo 27 is 3).
log2y = log23
So: y = 3.