Finding the Fourth Proportional to 865,665.07, 1,298,562.82 and 258,405.39

Step by Step Solution

1. Step 1: Write the proportion equation
   865,665.07 : 1,298,562.82 = 258,405.39 : x
2. Step 2: Convert to fraction form
   865,665.07/1,298,562.82 = 258,405.39/x
3. Step 3: Cross multiply
   865,665.07x = 1,298,562.82 × 258,405.39
4. Step 4: Simplify right side
   865,665.07x = 335,555,631,941.60
5. Step 5: Solve for x
   x = 335,555,631,941.60/865,665.07
6. Step 6: Final answer
   x = 387,627.55