Finding the Fourth Proportional to 1,222.86, 1,686.15 and 868.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.86 : 1,686.15 = 868.89 : x
2. Step 2: Convert to fraction form
   1,222.86/1,686.15 = 868.89/x
3. Step 3: Cross multiply
   1,222.86x = 1,686.15 × 868.89
4. Step 4: Simplify right side
   1,222.86x = 1,465,078.87
5. Step 5: Solve for x
   x = 1,465,078.87/1,222.86
6. Step 6: Final answer
   x = 1,198.08