Finding the Fourth Proportional to 1,392.46, 1,921.02 and 868.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.46 : 1,921.02 = 868.20 : x
2. Step 2: Convert to fraction form
   1,392.46/1,921.02 = 868.20/x
3. Step 3: Cross multiply
   1,392.46x = 1,921.02 × 868.20
4. Step 4: Simplify right side
   1,392.46x = 1,667,829.56
5. Step 5: Solve for x
   x = 1,667,829.56/1,392.46
6. Step 6: Final answer
   x = 1,197.76