Finding the Fourth Proportional to 498,111.31, 687,446.63 and 304,632.21

Step by Step Solution

1. Step 1: Write the proportion equation
   498,111.31 : 687,446.63 = 304,632.21 : x
2. Step 2: Convert to fraction form
   498,111.31/687,446.63 = 304,632.21/x
3. Step 3: Cross multiply
   498,111.31x = 687,446.63 × 304,632.21
4. Step 4: Simplify right side
   498,111.31x = 209,418,386,153.95
5. Step 5: Solve for x
   x = 209,418,386,153.95/498,111.31
6. Step 6: Final answer
   x = 420,424.88