Finding the Fourth Proportional to 1,384.90, 1,911.20 and 787.49

Step by Step Solution

1. Step 1: Write the proportion equation
   1,384.90 : 1,911.20 = 787.49 : x
2. Step 2: Convert to fraction form
   1,384.90/1,911.20 = 787.49/x
3. Step 3: Cross multiply
   1,384.90x = 1,911.20 × 787.49
4. Step 4: Simplify right side
   1,384.90x = 1,505,044.56
5. Step 5: Solve for x
   x = 1,505,044.56/1,384.90
6. Step 6: Final answer
   x = 1,086.76