Answer:
To find the constant of proportionality between x and y, we need to determine the ratio of y to x when x is 5.
y/x = 12/5
To simplify this fraction, we can multiply both the numerator and denominator by 5:
y/x = 12/5
(5y)/x = 12
Now we can solve for the constant of proportionality by multiplying both sides by x:
5y = 12x
Dividing both sides by 5:
y = (12/5)x
Therefore, the constant of proportionality is 12/5 or 2.4.