Finding the Fourth Proportional to 22,758.78, 31,409.46 and 12,688.86

Step by Step Solution

1. Step 1: Write the proportion equation
   22,758.78 : 31,409.46 = 12,688.86 : x
2. Step 2: Convert to fraction form
   22,758.78/31,409.46 = 12,688.86/x
3. Step 3: Cross multiply
   22,758.78x = 31,409.46 × 12,688.86
4. Step 4: Simplify right side
   22,758.78x = 398,550,240.62
5. Step 5: Solve for x
   x = 398,550,240.62/22,758.78
6. Step 6: Final answer
   x = 17,511.93