Finding the Fourth Proportional to 498,108.50, 687,389.89 and 319,260.50

Step by Step Solution

1. Step 1: Write the proportion equation
   498,108.50 : 687,389.89 = 319,260.50 : x
2. Step 2: Convert to fraction form
   498,108.50/687,389.89 = 319,260.50/x
3. Step 3: Cross multiply
   498,108.50x = 687,389.89 × 319,260.50
4. Step 4: Simplify right side
   498,108.50x = 219,456,439,976.35
5. Step 5: Solve for x
   x = 219,456,439,976.35/498,108.50
6. Step 6: Final answer
   x = 440,579.59