Final answer:
The set of ordered pairs represents a relation but it is not a function because the input '2' corresponds to more than one output.
Step-by-step explanation:
The set of ordered pairs (2, 3.5), (3, 7.8), (2, 6.9), (4, 3.8) represents a relation because it connects elements from one set (the first components, representing the x-coordinates) with elements from another set (the second components, representing the y-coordinates).
However, this set of ordered pairs is not a function. In a function, each input (or x-coordinate) must correspond to exactly one output (or y-coordinate). Since the input '2' is associated with two different outputs '3.5' and '6.9', this violates the definition of a function.
The second time the value '2' appears, it should have the same output value to maintain the definition of a function, which it does not in this case.