Finding the Fourth Proportional to 1,290.83, 1,935.21 and 559.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,290.83 : 1,935.21 = 559.89 : x
2. Step 2: Convert to fraction form
   1,290.83/1,935.21 = 559.89/x
3. Step 3: Cross multiply
   1,290.83x = 1,935.21 × 559.89
4. Step 4: Simplify right side
   1,290.83x = 1,083,504.73
5. Step 5: Solve for x
   x = 1,083,504.73/1,290.83
6. Step 6: Final answer
   x = 839.39