Finding the Fourth Proportional to 3,989.54, 5,505.30 and 2,221.10

Step by Step Solution

1. Step 1: Write the proportion equation
   3,989.54 : 5,505.30 = 2,221.10 : x
2. Step 2: Convert to fraction form
   3,989.54/5,505.30 = 2,221.10/x
3. Step 3: Cross multiply
   3,989.54x = 5,505.30 × 2,221.10
4. Step 4: Simplify right side
   3,989.54x = 12,227,821.83
5. Step 5: Solve for x
   x = 12,227,821.83/3,989.54
6. Step 6: Final answer
   x = 3,064.97