Finding the Fourth Proportional to 1,392.96, 1,920.72 and 868.32

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.96 : 1,920.72 = 868.32 : x
2. Step 2: Convert to fraction form
   1,392.96/1,920.72 = 868.32/x
3. Step 3: Cross multiply
   1,392.96x = 1,920.72 × 868.32
4. Step 4: Simplify right side
   1,392.96x = 1,667,799.59
5. Step 5: Solve for x
   x = 1,667,799.59/1,392.96
6. Step 6: Final answer
   x = 1,197.31