Finding the Fourth Proportional to 7,043.78, 9,720.06 and 3,900.18

Step by Step Solution

1. Step 1: Write the proportion equation
   7,043.78 : 9,720.06 = 3,900.18 : x
2. Step 2: Convert to fraction form
   7,043.78/9,720.06 = 3,900.18/x
3. Step 3: Cross multiply
   7,043.78x = 9,720.06 × 3,900.18
4. Step 4: Simplify right side
   7,043.78x = 37,909,983.61
5. Step 5: Solve for x
   x = 37,909,983.61/7,043.78
6. Step 6: Final answer
   x = 5,382.05