Finding the Fourth Proportional to 6,839.20, 9,428.72 and 4,320.05

Step by Step Solution

1. Step 1: Write the proportion equation
   6,839.20 : 9,428.72 = 4,320.05 : x
2. Step 2: Convert to fraction form
   6,839.20/9,428.72 = 4,320.05/x
3. Step 3: Cross multiply
   6,839.20x = 9,428.72 × 4,320.05
4. Step 4: Simplify right side
   6,839.20x = 40,732,550.43
5. Step 5: Solve for x
   x = 40,732,550.43/6,839.20
6. Step 6: Final answer
   x = 5,955.75