Which of the following is not a proportion?

Proportions are when two ratios are equal. Let’s take a look at each one

1.5/3 = 3/9. The top portion looks to increase by 2 times but the bottom is by 3 times. Need to mark that one as questionable. Let’s continue

22/33 = 4/6. Top number was reduced by 5.5 times and so was bottom number (33/5.5 is 6).

2/3 = 142/213. Top number increased by 71 times and so was the bottom number (3x71 is 213).

14/7 = 7/3.5. Top number reduced by 2 times and so was the bottom number (7/2 is 3.5).

Thus our concern of the first set of ratios being questionable was correct. The first set of data is NOT a proportion.