1. relative frequency and experimental probability represent the same ratio.
true or false
2. a function is a relation in which each input has at least one output. true or false
3. the x-axis on a coordinate plane is the vertical axis. true false
4. in a direct variation, the constant of proportionality, constant of variation, and unit rate represent the same value.

1. Relative frequency and experimental probability represent the same ratio - TRUE

2. A function is a relation in which each input has at least one output. FALSE

3. The x-axis on a coordinate plane is the vertical axis. FALSE

4. In a direct variation, the constant of proportionality, constant of variation, and unit rate represent the same value. TRUE

sample answer: you can determine whether each element of the domain is paired with exactly one element of the range. for example, if given a graph, you could use the vertical line test; if a vertical line intersects the graph more than once, then the relation that the graph represents is not a function.