Answer:
they are proportional
Explanation:
to find if they are proportional, we will take x/y ratios and compare several of them, it will tell us if they are proportional or not and give us the constant of proportionality
x1/y1 = 21/3 = 7/1
x2 / y2 = 70 / 10 = 7 / 1
x3 / y3 = 49 /7 = 7 / 1
Since the x/y ration does not change, they are proportional, which means that whatever the value of y, the value of x will be y multiplied by the constant of proportionality
and the constant of proportionality is 7