Finding the Fourth Proportional to 22,709.20, 31,338.72 and 12,638.56

Step by Step Solution

1. Step 1: Write the proportion equation
   22,709.20 : 31,338.72 = 12,638.56 : x
2. Step 2: Convert to fraction form
   22,709.20/31,338.72 = 12,638.56/x
3. Step 3: Cross multiply
   22,709.20x = 31,338.72 × 12,638.56
4. Step 4: Simplify right side
   22,709.20x = 396,076,293.04
5. Step 5: Solve for x
   x = 396,076,293.04/22,709.20
6. Step 6: Final answer
   x = 17,441.23