Finding the Fourth Proportional to 1,399.16, 1,931.34 and 868.13

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.16 : 1,931.34 = 868.13 : x
2. Step 2: Convert to fraction form
   1,399.16/1,931.34 = 868.13/x
3. Step 3: Cross multiply
   1,399.16x = 1,931.34 × 868.13
4. Step 4: Simplify right side
   1,399.16x = 1,676,665.90
5. Step 5: Solve for x
   x = 1,676,665.90/1,399.16
6. Step 6: Final answer
   x = 1,198.34