Finding the Fourth Proportional to 1,399.41, 1,930.32 and 868.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.41 : 1,930.32 = 868.55 : x
2. Step 2: Convert to fraction form
   1,399.41/1,930.32 = 868.55/x
3. Step 3: Cross multiply
   1,399.41x = 1,930.32 × 868.55
4. Step 4: Simplify right side
   1,399.41x = 1,676,569.78
5. Step 5: Solve for x
   x = 1,676,569.78/1,399.41
6. Step 6: Final answer
   x = 1,198.05