Finding the Fourth Proportional to 1,142.80, 1,577.05 and 618.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.80 : 1,577.05 = 618.83 : x
2. Step 2: Convert to fraction form
   1,142.80/1,577.05 = 618.83/x
3. Step 3: Cross multiply
   1,142.80x = 1,577.05 × 618.83
4. Step 4: Simplify right side
   1,142.80x = 975,925.85
5. Step 5: Solve for x
   x = 975,925.85/1,142.80
6. Step 6: Final answer
   x = 853.98