Finding the Fourth Proportional to 1,311.82, 1,809.56 and 787.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,311.82 : 1,809.56 = 787.54 : x
2. Step 2: Convert to fraction form
   1,311.82/1,809.56 = 787.54/x
3. Step 3: Cross multiply
   1,311.82x = 1,809.56 × 787.54
4. Step 4: Simplify right side
   1,311.82x = 1,425,100.88
5. Step 5: Solve for x
   x = 1,425,100.88/1,311.82
6. Step 6: Final answer
   x = 1,086.35