Finding the Fourth Proportional to 22,758.80, 31,407.72 and 12,688.88

Step by Step Solution

1. Step 1: Write the proportion equation
   22,758.80 : 31,407.72 = 12,688.88 : x
2. Step 2: Convert to fraction form
   22,758.80/31,407.72 = 12,688.88/x
3. Step 3: Cross multiply
   22,758.80x = 31,407.72 × 12,688.88
4. Step 4: Simplify right side
   22,758.80x = 398,528,790.15
5. Step 5: Solve for x
   x = 398,528,790.15/22,758.80
6. Step 6: Final answer
   x = 17,510.98