Finding the Fourth Proportional to 680,105.97, 1,018,758.87 and 398,945.25

Step by Step Solution

1. Step 1: Write the proportion equation
   680,105.97 : 1,018,758.87 = 398,945.25 : x
2. Step 2: Convert to fraction form
   680,105.97/1,018,758.87 = 398,945.25/x
3. Step 3: Cross multiply
   680,105.97x = 1,018,758.87 × 398,945.25
4. Step 4: Simplify right side
   680,105.97x = 406,429,012,081.87
5. Step 5: Solve for x
   x = 406,429,012,081.87/680,105.97
6. Step 6: Final answer
   x = 597,596.60