Finding the Fourth Proportional to 12,665.18, 18,999.72 and 5,647.61

Step by Step Solution

1. Step 1: Write the proportion equation
   12,665.18 : 18,999.72 = 5,647.61 : x
2. Step 2: Convert to fraction form
   12,665.18/18,999.72 = 5,647.61/x
3. Step 3: Cross multiply
   12,665.18x = 18,999.72 × 5,647.61
4. Step 4: Simplify right side
   12,665.18x = 107,302,913.67
5. Step 5: Solve for x
   x = 107,302,913.67/12,665.18
6. Step 6: Final answer
   x = 8,472.28