Finding the Fourth Proportional to 1,107.76, 1,661.82 and 559.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,107.76 : 1,661.82 = 559.72 : x
2. Step 2: Convert to fraction form
   1,107.76/1,661.82 = 559.72/x
3. Step 3: Cross multiply
   1,107.76x = 1,661.82 × 559.72
4. Step 4: Simplify right side
   1,107.76x = 930,153.89
5. Step 5: Solve for x
   x = 930,153.89/1,107.76
6. Step 6: Final answer
   x = 839.67