Finding the Fourth Proportional to 1,048.78, 1,447.71 and 787.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,048.78 : 1,447.71 = 787.55 : x
2. Step 2: Convert to fraction form
   1,048.78/1,447.71 = 787.55/x
3. Step 3: Cross multiply
   1,048.78x = 1,447.71 × 787.55
4. Step 4: Simplify right side
   1,048.78x = 1,140,144.01
5. Step 5: Solve for x
   x = 1,140,144.01/1,048.78
6. Step 6: Final answer
   x = 1,087.11