Finding the Fourth Proportional to 2,028.60, 2,798.89 and 1,399.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,028.60 : 2,798.89 = 1,399.30 : x
2. Step 2: Convert to fraction form
   2,028.60/2,798.89 = 1,399.30/x
3. Step 3: Cross multiply
   2,028.60x = 2,798.89 × 1,399.30
4. Step 4: Simplify right side
   2,028.60x = 3,916,476.28
5. Step 5: Solve for x
   x = 3,916,476.28/2,028.60
6. Step 6: Final answer
   x = 1,930.63