Finding the Fourth Proportional to 23,139.30, 31,932.24 and 12,528.90

Step by Step Solution

1. Step 1: Write the proportion equation
   23,139.30 : 31,932.24 = 12,528.90 : x
2. Step 2: Convert to fraction form
   23,139.30/31,932.24 = 12,528.90/x
3. Step 3: Cross multiply
   23,139.30x = 31,932.24 × 12,528.90
4. Step 4: Simplify right side
   23,139.30x = 400,075,841.74
5. Step 5: Solve for x
   x = 400,075,841.74/23,139.30
6. Step 6: Final answer
   x = 17,289.89