Andrew drives his car 145.5 miles in 3 hours. What is the constant of proportionality that related the total of miles, y, to the number of hours, x?

48.5

Step-by-step 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