Answer
a. Yes, the relation is a function.
b. No, because 6 would be paired with both 2.5 and 3.0.
Work Step by Step
a. Each element in the domain corresponds with exactly one element in the range.
b. An element (6) in the range corresponds with more than one element (2.5 and 3.0) in the domain. Values from the range can pair with more than one of the values in the domain, but this property cannot be reversed.