Finding the Fourth Proportional to 1,413.82, 2,120.78 and 439.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,413.82 : 2,120.78 = 439.93 : x
2. Step 2: Convert to fraction form
   1,413.82/2,120.78 = 439.93/x
3. Step 3: Cross multiply
   1,413.82x = 2,120.78 × 439.93
4. Step 4: Simplify right side
   1,413.82x = 932,998.50
5. Step 5: Solve for x
   x = 932,998.50/1,413.82
6. Step 6: Final answer
   x = 659.91