Answer:
the constant proportionality means the ratio between two directly proportional quantities.
so the constant proportionality will be 7.5÷6=1.25 or 10÷8=1.25 or 12.5÷10=1.25
constant proportionality should be same all through because it's a constant
I believe it is the second one hope that helped
Step-by-step explanation:
Average between these no.s =


approx