Finding the Fourth Proportional to 23,139.20, 31,932.17 and 12,528.81

Step by Step Solution

1. Step 1: Write the proportion equation
   23,139.20 : 31,932.17 = 12,528.81 : x
2. Step 2: Convert to fraction form
   23,139.20/31,932.17 = 12,528.81/x
3. Step 3: Cross multiply
   23,139.20x = 31,932.17 × 12,528.81
4. Step 4: Simplify right side
   23,139.20x = 400,072,028.17
5. Step 5: Solve for x
   x = 400,072,028.17/23,139.20
6. Step 6: Final answer
   x = 17,289.80