Finding the Fourth Proportional to 1,105.57, 1,658.49 and 542.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,105.57 : 1,658.49 = 542.89 : x
2. Step 2: Convert to fraction form
   1,105.57/1,658.49 = 542.89/x
3. Step 3: Cross multiply
   1,105.57x = 1,658.49 × 542.89
4. Step 4: Simplify right side
   1,105.57x = 900,377.64
5. Step 5: Solve for x
   x = 900,377.64/1,105.57
6. Step 6: Final answer
   x = 814.40