Finding the Fourth Proportional to 1,289.96, 1,935.72 and 559.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,289.96 : 1,935.72 = 559.56 : x
2. Step 2: Convert to fraction form
   1,289.96/1,935.72 = 559.56/x
3. Step 3: Cross multiply
   1,289.96x = 1,935.72 × 559.56
4. Step 4: Simplify right side
   1,289.96x = 1,083,151.48
5. Step 5: Solve for x
   x = 1,083,151.48/1,289.96
6. Step 6: Final answer
   x = 839.68