Answer:
A positive statement seeks to describe or explain something based on empirical evidence, while a normative statement seeks to recommend something, or to express a subjective opinion.
a. The federal minimum wage is increasing to $6.50 an hour. - Positive statement. It is stating a fact, not telling us whether this rise in the minimum wage is good or bad.
b. The minimum wage should be high enough that families will not live in poverty. - This is a classical normative statement. It is giving an opinion, and recommending a policy.
