Finding the Fourth Proportional to 1,116.20, 1,540.33 and 618.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,116.20 : 1,540.33 = 618.83 : x
2. Step 2: Convert to fraction form
   1,116.20/1,540.33 = 618.83/x
3. Step 3: Cross multiply
   1,116.20x = 1,540.33 × 618.83
4. Step 4: Simplify right side
   1,116.20x = 953,198.94
5. Step 5: Solve for x
   x = 953,198.94/1,116.20
6. Step 6: Final answer
   x = 853.97