Ratio and Proportion - General Questions

Find the fourth proportional to 2, 11 and 12.

Two numbers are in the ratio 4 : 7. If 13 is added to each, the ratio becomes 37 : 55. What is the smaller number?

Two numbers are in the ratio 1 : 7. If 9 is added to each, the ratio becomes 8 : 29. What is the smaller number?

Find the mean proportional between 36 and 144.

Find the fourth proportional to 11, 5 and 11.