Finding the Fourth Proportional to 9,889.56, 13,647.78 and 5,413.28

Step by Step Solution

1. Step 1: Write the proportion equation
   9,889.56 : 13,647.78 = 5,413.28 : x
2. Step 2: Convert to fraction form
   9,889.56/13,647.78 = 5,413.28/x
3. Step 3: Cross multiply
   9,889.56x = 13,647.78 × 5,413.28
4. Step 4: Simplify right side
   9,889.56x = 73,879,186.28
5. Step 5: Solve for x
   x = 73,879,186.28/9,889.56
6. Step 6: Final answer
   x = 7,470.42