Finding the Fourth Proportional to 1,380.92, 1,905.94 and 791.85

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.92 : 1,905.94 = 791.85 : x
2. Step 2: Convert to fraction form
   1,380.92/1,905.94 = 791.85/x
3. Step 3: Cross multiply
   1,380.92x = 1,905.94 × 791.85
4. Step 4: Simplify right side
   1,380.92x = 1,509,218.59
5. Step 5: Solve for x
   x = 1,509,218.59/1,380.92
6. Step 6: Final answer
   x = 1,092.91