Finding the Fourth Proportional to 1,105.59, 1,658.39 and 618.87

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.59 : 1,658.39 = 618.87 : x
2. Step 2: Convert to fraction form
   1,105.59/1,658.39 = 618.87/x
3. Step 3: Cross multiply
   1,105.59x = 1,658.39 × 618.87
4. Step 4: Simplify right side
   1,105.59x = 1,026,324.72
5. Step 5: Solve for x
   x = 1,026,324.72/1,105.59
6. Step 6: Final answer
   x = 928.31