Finding the Fourth Proportional to 12,405.56, 18,610.16 and 3,639.32

Step by Step Solution

1. Step 1: Write the proportion equation
   12,405.56 : 18,610.16 = 3,639.32 : x
2. Step 2: Convert to fraction form
   12,405.56/18,610.16 = 3,639.32/x
3. Step 3: Cross multiply
   12,405.56x = 18,610.16 × 3,639.32
4. Step 4: Simplify right side
   12,405.56x = 67,728,327.49
5. Step 5: Solve for x
   x = 67,728,327.49/12,405.56
6. Step 6: Final answer
   x = 5,459.51