Finding the Fourth Proportional to 660,822.88, 911,917.83 and 388,906.78

Step by Step Solution

1. Step 1: Write the proportion equation
   660,822.88 : 911,917.83 = 388,906.78 : x
2. Step 2: Convert to fraction form
   660,822.88/911,917.83 = 388,906.78/x
3. Step 3: Cross multiply
   660,822.88x = 911,917.83 × 388,906.78
4. Step 4: Simplify right side
   660,822.88x = 354,651,026,889.89
5. Step 5: Solve for x
   x = 354,651,026,889.89/660,822.88
6. Step 6: Final answer
   x = 536,680.91