Finding the Fourth Proportional to 10,930.75, 16,398.90 and 3,139.57

Step by Step Solution

1. Step 1: Write the proportion equation
   10,930.75 : 16,398.90 = 3,139.57 : x
2. Step 2: Convert to fraction form
   10,930.75/16,398.90 = 3,139.57/x
3. Step 3: Cross multiply
   10,930.75x = 16,398.90 × 3,139.57
4. Step 4: Simplify right side
   10,930.75x = 51,485,494.47
5. Step 5: Solve for x
   x = 51,485,494.47/10,930.75
6. Step 6: Final answer
   x = 4,710.15