Finding the Fourth Proportional to 1,571.55, 2,168.78 and 863.43

Step by Step Solution

1. Step 1: Write the proportion equation
   1,571.55 : 2,168.78 = 863.43 : x
2. Step 2: Convert to fraction form
   1,571.55/2,168.78 = 863.43/x
3. Step 3: Cross multiply
   1,571.55x = 2,168.78 × 863.43
4. Step 4: Simplify right side
   1,571.55x = 1,872,589.72
5. Step 5: Solve for x
   x = 1,872,589.72/1,571.55
6. Step 6: Final answer
   x = 1,191.56