Finding the Fourth Proportional to 12,456.31, 18,681.27 and 3,689.17

Step by Step Solution

1. Step 1: Write the proportion equation
   12,456.31 : 18,681.27 = 3,689.17 : x
2. Step 2: Convert to fraction form
   12,456.31/18,681.27 = 3,689.17/x
3. Step 3: Cross multiply
   12,456.31x = 18,681.27 × 3,689.17
4. Step 4: Simplify right side
   12,456.31x = 68,918,380.85
5. Step 5: Solve for x
   x = 68,918,380.85/12,456.31
6. Step 6: Final answer
   x = 5,532.81