Finding the Fourth Proportional to 22,758.69, 31,408.05 and 12,687.20

Step by Step Solution

1. Step 1: Write the proportion equation
   22,758.69 : 31,408.05 = 12,687.20 : x
2. Step 2: Convert to fraction form
   22,758.69/31,408.05 = 12,687.20/x
3. Step 3: Cross multiply
   22,758.69x = 31,408.05 × 12,687.20
4. Step 4: Simplify right side
   22,758.69x = 398,480,211.96
5. Step 5: Solve for x
   x = 398,480,211.96/22,758.69
6. Step 6: Final answer
   x = 17,508.93