Finding the Fourth Proportional to 1,413.30, 2,120.55 and 763.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,413.30 : 2,120.55 = 763.89 : x
2. Step 2: Convert to fraction form
   1,413.30/2,120.55 = 763.89/x
3. Step 3: Cross multiply
   1,413.30x = 2,120.55 × 763.89
4. Step 4: Simplify right side
   1,413.30x = 1,619,866.94
5. Step 5: Solve for x
   x = 1,619,866.94/1,413.30
6. Step 6: Final answer
   x = 1,146.16