5. i, ii, iii, iv, v,
conjecture:

12/5

Step-by-step explanation:

when you are trying to find a missing value, you do the recipical. example with this problem, it is 5/12. it is division so you would multiply. the way you do that is flip the fraction like this: 12/5. than you multiply 12/5 by 1 (or 1/1 *same thing*). Than your answer is 12/5.

here is an example for when you have to divide: 5×__=25. you would divide 5 from each side and your answer would be 5.