Finding the Fourth Proportional to 2,025.88, 3,038.78 and 639.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,025.88 : 3,038.78 = 639.30 : x
2. Step 2: Convert to fraction form
   2,025.88/3,038.78 = 639.30/x
3. Step 3: Cross multiply
   2,025.88x = 3,038.78 × 639.30
4. Step 4: Simplify right side
   2,025.88x = 1,942,705.05
5. Step 5: Solve for x
   x = 1,942,705.05/2,025.88
6. Step 6: Final answer
   x = 958.94