Finding the Fourth Proportional to 705,513.78, 1,057,545.72 and 278,876.25

Step by Step Solution

1. Step 1: Write the proportion equation
   705,513.78 : 1,057,545.72 = 278,876.25 : x
2. Step 2: Convert to fraction form
   705,513.78/1,057,545.72 = 278,876.25/x
3. Step 3: Cross multiply
   705,513.78x = 1,057,545.72 × 278,876.25
4. Step 4: Simplify right side
   705,513.78x = 294,924,384,597.15
5. Step 5: Solve for x
   x = 294,924,384,597.15/705,513.78
6. Step 6: Final answer
   x = 418,027.82