Finding the Fourth Proportional to 9,413.72, 12,990.98 and 5,165.18

Step by Step Solution

1. Step 1: Write the proportion equation
   9,413.72 : 12,990.98 = 5,165.18 : x
2. Step 2: Convert to fraction form
   9,413.72/12,990.98 = 5,165.18/x
3. Step 3: Cross multiply
   9,413.72x = 12,990.98 × 5,165.18
4. Step 4: Simplify right side
   9,413.72x = 67,100,819.82
5. Step 5: Solve for x
   x = 67,100,819.82/9,413.72
6. Step 6: Final answer
   x = 7,127.98