Finding the Fourth Proportional to 21,139.56, 29,172.52 and 12,187.02

Step by Step Solution

1. Step 1: Write the proportion equation
   21,139.56 : 29,172.52 = 12,187.02 : x
2. Step 2: Convert to fraction form
   21,139.56/29,172.52 = 12,187.02/x
3. Step 3: Cross multiply
   21,139.56x = 29,172.52 × 12,187.02
4. Step 4: Simplify right side
   21,139.56x = 355,526,084.69
5. Step 5: Solve for x
   x = 355,526,084.69/21,139.56
6. Step 6: Final answer
   x = 16,818.05