Finding the Fourth Proportional to 1,392.15, 1,921.20 and 794.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,392.15 : 1,921.20 = 794.78 : x
2. Step 2: Convert to fraction form
   1,392.15/1,921.20 = 794.78/x
3. Step 3: Cross multiply
   1,392.15x = 1,921.20 × 794.78
4. Step 4: Simplify right side
   1,392.15x = 1,526,921.73
5. Step 5: Solve for x
   x = 1,526,921.73/1,392.15
6. Step 6: Final answer
   x = 1,096.81