Finding the Fourth Proportional to 9,413.56, 12,990.16 and 5,380.83

Step by Step Solution

1. Step 1: Write the proportion equation
   9,413.56 : 12,990.16 = 5,380.83 : x
2. Step 2: Convert to fraction form
   9,413.56/12,990.16 = 5,380.83/x
3. Step 3: Cross multiply
   9,413.56x = 12,990.16 × 5,380.83
4. Step 4: Simplify right side
   9,413.56x = 69,897,750.78
5. Step 5: Solve for x
   x = 69,897,750.78/9,413.56
6. Step 6: Final answer
   x = 7,425.22