Finding the Fourth Proportional to 12,086.27, 18,128.67 and 7,187.09

Step by Step Solution

1. Step 1: Write the proportion equation
   12,086.27 : 18,128.67 = 7,187.09 : x
2. Step 2: Convert to fraction form
   12,086.27/18,128.67 = 7,187.09/x
3. Step 3: Cross multiply
   12,086.27x = 18,128.67 × 7,187.09
4. Step 4: Simplify right side
   12,086.27x = 130,292,382.87
5. Step 5: Solve for x
   x = 130,292,382.87/12,086.27
6. Step 6: Final answer
   x = 10,780.20