Final answer:
If the price of a complement falls, then the demand for plasma televisions will increase.
Step-by-step explanation:
Plasma televisions are a normal good, which means that as income increases, the demand for plasma televisions increases. If the price of a complement, or a good that is used together with plasma televisions, falls, then the demand for plasma televisions will increase. This is because a lower price for the complement good will make it more affordable and encourage people to buy more plasma televisions.