Finding the Fourth Proportional to 12,309.10, 18,442.05 and 10,105.90

Step by Step Solution

1. Step 1: Write the proportion equation
   12,309.10 : 18,442.05 = 10,105.90 : x
2. Step 2: Convert to fraction form
   12,309.10/18,442.05 = 10,105.90/x
3. Step 3: Cross multiply
   12,309.10x = 18,442.05 × 10,105.90
4. Step 4: Simplify right side
   12,309.10x = 186,373,513.10
5. Step 5: Solve for x
   x = 186,373,513.10/12,309.10
6. Step 6: Final answer
   x = 15,141.12