Finding the Fourth Proportional to 12,485.72, 18,729.83 and 4,165.78

Step by Step Solution

1. Step 1: Write the proportion equation
   12,485.72 : 18,729.83 = 4,165.78 : x
2. Step 2: Convert to fraction form
   12,485.72/18,729.83 = 4,165.78/x
3. Step 3: Cross multiply
   12,485.72x = 18,729.83 × 4,165.78
4. Step 4: Simplify right side
   12,485.72x = 78,024,349.93
5. Step 5: Solve for x
   x = 78,024,349.93/12,485.72
6. Step 6: Final answer
   x = 6,249.09