number two is proportional just do Y over X y/x meaning divided all the y’s over the x’s so 25 divided by 5 30 divided by 6 35/7 40/8 they all equal 5 so it’s proportional
number three isn’t proportional when you do y/x they all come out differently so you do y2-y1 over x2-x1 16-4/4-2 16-4=12 4-2=2 then you divided 12/2 that equals 6 you do that again but with the next numbers but they don’t equal so it’s no equation no constant