Finding the Fourth Proportional to 1,280.41, 1,920.86 and 414.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,280.41 : 1,920.86 = 414.61 : x
2. Step 2: Convert to fraction form
   1,280.41/1,920.86 = 414.61/x
3. Step 3: Cross multiply
   1,280.41x = 1,920.86 × 414.61
4. Step 4: Simplify right side
   1,280.41x = 796,405.69
5. Step 5: Solve for x
   x = 796,405.69/1,280.41
6. Step 6: Final answer
   x = 621.99