Finding the Fourth Proportional to 1,380.71, 1,905.46 and 791.24

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.71 : 1,905.46 = 791.24 : x
2. Step 2: Convert to fraction form
   1,380.71/1,905.46 = 791.24/x
3. Step 3: Cross multiply
   1,380.71x = 1,905.46 × 791.24
4. Step 4: Simplify right side
   1,380.71x = 1,507,664.67
5. Step 5: Solve for x
   x = 1,507,664.67/1,380.71
6. Step 6: Final answer
   x = 1,091.95