Finding the Fourth Proportional to 2,577.80, 3,557.39 and 1,398.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,577.80 : 3,557.39 = 1,398.89 : x
2. Step 2: Convert to fraction form
   2,577.80/3,557.39 = 1,398.89/x
3. Step 3: Cross multiply
   2,577.80x = 3,557.39 × 1,398.89
4. Step 4: Simplify right side
   2,577.80x = 4,976,399.20
5. Step 5: Solve for x
   x = 4,976,399.20/2,577.80
6. Step 6: Final answer
   x = 1,930.48