Finding the Fourth Proportional to 22,761.51, 31,410.79 and 12,688.55

Step by Step Solution

1. Step 1: Write the proportion equation
   22,761.51 : 31,410.79 = 12,688.55 : x
2. Step 2: Convert to fraction form
   22,761.51/31,410.79 = 12,688.55/x
3. Step 3: Cross multiply
   22,761.51x = 31,410.79 × 12,688.55
4. Step 4: Simplify right side
   22,761.51x = 398,557,308.47
5. Step 5: Solve for x
   x = 398,557,308.47/22,761.51
6. Step 6: Final answer
   x = 17,510.15