Finding the Fourth Proportional to 6,425.40, 9,635.40 and 3,139.50

Step by Step Solution

1. Step 1: Write the proportion equation
   6,425.40 : 9,635.40 = 3,139.50 : x
2. Step 2: Convert to fraction form
   6,425.40/9,635.40 = 3,139.50/x
3. Step 3: Cross multiply
   6,425.40x = 9,635.40 × 3,139.50
4. Step 4: Simplify right side
   6,425.40x = 30,250,338.30
5. Step 5: Solve for x
   x = 30,250,338.30/6,425.40
6. Step 6: Final answer
   x = 4,707.93