Finding the Fourth Proportional to 4,399.78, 6,068.10 and 3,138.61

Step by Step Solution

1. Step 1: Write the proportion equation
   4,399.78 : 6,068.10 = 3,138.61 : x
2. Step 2: Convert to fraction form
   4,399.78/6,068.10 = 3,138.61/x
3. Step 3: Cross multiply
   4,399.78x = 6,068.10 × 3,138.61
4. Step 4: Simplify right side
   4,399.78x = 19,045,399.34
5. Step 5: Solve for x
   x = 19,045,399.34/4,399.78
6. Step 6: Final answer
   x = 4,328.72