Finding the Fourth Proportional to 12,139.56, 18,211.42 and 5,566.31

Step by Step Solution

1. Step 1: Write the proportion equation
   12,139.56 : 18,211.42 = 5,566.31 : x
2. Step 2: Convert to fraction form
   12,139.56/18,211.42 = 5,566.31/x
3. Step 3: Cross multiply
   12,139.56x = 18,211.42 × 5,566.31
4. Step 4: Simplify right side
   12,139.56x = 101,370,409.26
5. Step 5: Solve for x
   x = 101,370,409.26/12,139.56
6. Step 6: Final answer
   x = 8,350.42