Finding the Fourth Proportional to 1,380.95, 1,905.89 and 791.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.95 : 1,905.89 = 791.61 : x
2. Step 2: Convert to fraction form
   1,380.95/1,905.89 = 791.61/x
3. Step 3: Cross multiply
   1,380.95x = 1,905.89 × 791.61
4. Step 4: Simplify right side
   1,380.95x = 1,508,717.62
5. Step 5: Solve for x
   x = 1,508,717.62/1,380.95
6. Step 6: Final answer
   x = 1,092.53