Finding the Fourth Proportional to 12,431.72, 18,641.10 and 3,665.48

Step by Step Solution

1. Step 1: Write the proportion equation
   12,431.72 : 18,641.10 = 3,665.48 : x
2. Step 2: Convert to fraction form
   12,431.72/18,641.10 = 3,665.48/x
3. Step 3: Cross multiply
   12,431.72x = 18,641.10 × 3,665.48
4. Step 4: Simplify right side
   12,431.72x = 68,328,579.23
5. Step 5: Solve for x
   x = 68,328,579.23/12,431.72
6. Step 6: Final answer
   x = 5,496.31