Finding the Fourth Proportional to 2,628.57, 3,940.41 and 986.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,628.57 : 3,940.41 = 986.21 : x
2. Step 2: Convert to fraction form
   2,628.57/3,940.41 = 986.21/x
3. Step 3: Cross multiply
   2,628.57x = 3,940.41 × 986.21
4. Step 4: Simplify right side
   2,628.57x = 3,886,052.04
5. Step 5: Solve for x
   x = 3,886,052.04/2,628.57
6. Step 6: Final answer
   x = 1,478.39