Answer:
48.5
Explanation:
The constant of proportionality in this case is the speed at which Andrew travels.
We know that the speed is equal to:
v = d / t
We know the distance that is 145.5 miles and the time is 3 hours, replacing:
v = 145.5 / 3
v = 48.5 mi / h
which means that the equation would be:
y = k * x
where k, that is, the constant of proportionality is the velocity 48.5.
y = 48.5 * x
To check if for example x is worth 3, it would be:
y = 48.5 * 3
y = 145.5