Finding the Fourth Proportional to 12,149.57, 18,192.83 and 10,405.78

Step by Step Solution

1. Step 1: Write the proportion equation
   12,149.57 : 18,192.83 = 10,405.78 : x
2. Step 2: Convert to fraction form
   12,149.57/18,192.83 = 10,405.78/x
3. Step 3: Cross multiply
   12,149.57x = 18,192.83 × 10,405.78
4. Step 4: Simplify right side
   12,149.57x = 189,310,606.03
5. Step 5: Solve for x
   x = 189,310,606.03/12,149.57
6. Step 6: Final answer
   x = 15,581.67