Finding the Fourth Proportional to 1,380.96, 1,905.56 and 791.36

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.96 : 1,905.56 = 791.36 : x
2. Step 2: Convert to fraction form
   1,380.96/1,905.56 = 791.36/x
3. Step 3: Cross multiply
   1,380.96x = 1,905.56 × 791.36
4. Step 4: Simplify right side
   1,380.96x = 1,507,983.96
5. Step 5: Solve for x
   x = 1,507,983.96/1,380.96
6. Step 6: Final answer
   x = 1,091.98