Finding the Fourth Proportional to 8,985.39, 12,399.12 and 5,450.55

Step by Step Solution

1. Step 1: Write the proportion equation
   8,985.39 : 12,399.12 = 5,450.55 : x
2. Step 2: Convert to fraction form
   8,985.39/12,399.12 = 5,450.55/x
3. Step 3: Cross multiply
   8,985.39x = 12,399.12 × 5,450.55
4. Step 4: Simplify right side
   8,985.39x = 67,582,023.52
5. Step 5: Solve for x
   x = 67,582,023.52/8,985.39
6. Step 6: Final answer
   x = 7,521.32