Finding the Fourth Proportional to 8,139.81, 12,211.31 and 3,459.77

Step by Step Solution

1. Step 1: Write the proportion equation
   8,139.81 : 12,211.31 = 3,459.77 : x
2. Step 2: Convert to fraction form
   8,139.81/12,211.31 = 3,459.77/x
3. Step 3: Cross multiply
   8,139.81x = 12,211.31 × 3,459.77
4. Step 4: Simplify right side
   8,139.81x = 42,248,324.00
5. Step 5: Solve for x
   x = 42,248,324.00/8,139.81
6. Step 6: Final answer
   x = 5,190.33