Finding the Fourth Proportional to 21,139.12, 29,172.20 and 12,754

Step by Step Solution

1. Step 1: Write the proportion equation
   21,139.12 : 29,172.20 = 12,754 : x
2. Step 2: Convert to fraction form
   21,139.12/29,172.20 = 12,754/x
3. Step 3: Cross multiply
   21,139.12x = 29,172.20 × 12,754
4. Step 4: Simplify right side
   21,139.12x = 372,062,238.80
5. Step 5: Solve for x
   x = 372,062,238.80/21,139.12
6. Step 6: Final answer
   x = 17,600.65