Finding the Fourth Proportional to 858,128.96, 1,287,401.52 and 259,054.34

Step by Step Solution

1. Step 1: Write the proportion equation
   858,128.96 : 1,287,401.52 = 259,054.34 : x
2. Step 2: Convert to fraction form
   858,128.96/1,287,401.52 = 259,054.34/x
3. Step 3: Cross multiply
   858,128.96x = 1,287,401.52 × 259,054.34
4. Step 4: Simplify right side
   858,128.96x = 333,506,951,078.60
5. Step 5: Solve for x
   x = 333,506,951,078.60/858,128.96
6. Step 6: Final answer
   x = 388,644.33