Finding the Fourth Proportional to 18,139.10, 25,342.90 and 18,139.10

Step by Step Solution

1. Step 1: Write the proportion equation
   18,139.10 : 25,342.90 = 18,139.10 : x
2. Step 2: Convert to fraction form
   18,139.10/25,342.90 = 18,139.10/x
3. Step 3: Cross multiply
   18,139.10x = 25,342.90 × 18,139.10
4. Step 4: Simplify right side
   18,139.10x = 459,697,397.39
5. Step 5: Solve for x
   x = 459,697,397.39/18,139.10
6. Step 6: Final answer
   x = 25,342.90