Finding the Fourth Proportional to 3,989.84, 5,505.98 and 2,221.61

Step by Step Solution

1. Step 1: Write the proportion equation
   3,989.84 : 5,505.98 = 2,221.61 : x
2. Step 2: Convert to fraction form
   3,989.84/5,505.98 = 2,221.61/x
3. Step 3: Cross multiply
   3,989.84x = 5,505.98 × 2,221.61
4. Step 4: Simplify right side
   3,989.84x = 12,232,101.59
5. Step 5: Solve for x
   x = 12,232,101.59/3,989.84
6. Step 6: Final answer
   x = 3,065.82