Finding the Fourth Proportional to 5,639.52, 7,778.90 and 3,872.10

Step by Step Solution

1. Step 1: Write the proportion equation
   5,639.52 : 7,778.90 = 3,872.10 : x
2. Step 2: Convert to fraction form
   5,639.52/7,778.90 = 3,872.10/x
3. Step 3: Cross multiply
   5,639.52x = 7,778.90 × 3,872.10
4. Step 4: Simplify right side
   5,639.52x = 30,120,678.69
5. Step 5: Solve for x
   x = 30,120,678.69/5,639.52
6. Step 6: Final answer
   x = 5,341.00