Answer
The maximum wattage is 200.49
The minimum wattage is 0
Work Step by Step
$W = VI$
$W = (163~sin~120\pi t)(1.23~sin~120\pi t)$
$W = 200.49~sin^2~120\pi t$
The maximum wattage occurs when $sin~120\pi t = 1$.
The maximum wattage is $(200.49)(1)^2$ which is 200.49
The minimum wattage occurs when $sin~120\pi t = 0$.
The minimum wattage is $(200.49)(0)^2$ which is 0