Finding the Fourth Proportional to 643,398, 887,757.48 and 356,856.72

Step by Step Solution

1. Step 1: Write the proportion equation
   643,398 : 887,757.48 = 356,856.72 : x
2. Step 2: Convert to fraction form
   643,398/887,757.48 = 356,856.72/x
3. Step 3: Cross multiply
   643,398x = 887,757.48 × 356,856.72
4. Step 4: Simplify right side
   643,398x = 316,802,222,468.27
5. Step 5: Solve for x
   x = 316,802,222,468.27/643,398
6. Step 6: Final answer
   x = 492,389.19