Finding the Fourth Proportional to 1,142.80, 1,577.24 and 863.35

Step by Step Solution

1. Step 1: Write the proportion equation
   1,142.80 : 1,577.24 = 863.35 : x
2. Step 2: Convert to fraction form
   1,142.80/1,577.24 = 863.35/x
3. Step 3: Cross multiply
   1,142.80x = 1,577.24 × 863.35
4. Step 4: Simplify right side
   1,142.80x = 1,361,710.15
5. Step 5: Solve for x
   x = 1,361,710.15/1,142.80
6. Step 6: Final answer
   x = 1,191.56