Finding the Fourth Proportional to 5,898.80, 8,139.48 and 3,906.20

Step by Step Solution

1. Step 1: Write the proportion equation
   5,898.80 : 8,139.48 = 3,906.20 : x
2. Step 2: Convert to fraction form
   5,898.80/8,139.48 = 3,906.20/x
3. Step 3: Cross multiply
   5,898.80x = 8,139.48 × 3,906.20
4. Step 4: Simplify right side
   5,898.80x = 31,794,436.78
5. Step 5: Solve for x
   x = 31,794,436.78/5,898.80
6. Step 6: Final answer
   x = 5,389.98