Finding the Fourth Proportional to 691,978.39, 954,908.52 and 405,689.15

Step by Step Solution

1. Step 1: Write the proportion equation
   691,978.39 : 954,908.52 = 405,689.15 : x
2. Step 2: Convert to fraction form
   691,978.39/954,908.52 = 405,689.15/x
3. Step 3: Cross multiply
   691,978.39x = 954,908.52 × 405,689.15
4. Step 4: Simplify right side
   691,978.39x = 387,396,025,806.56
5. Step 5: Solve for x
   x = 387,396,025,806.56/691,978.39
6. Step 6: Final answer
   x = 559,838.33