Finding the Fourth Proportional to 1,531.57, 2,113.55 and 868.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,531.57 : 2,113.55 = 868.55 : x
2. Step 2: Convert to fraction form
   1,531.57/2,113.55 = 868.55/x
3. Step 3: Cross multiply
   1,531.57x = 2,113.55 × 868.55
4. Step 4: Simplify right side
   1,531.57x = 1,835,723.85
5. Step 5: Solve for x
   x = 1,835,723.85/1,531.57
6. Step 6: Final answer
   x = 1,198.59