Finding the Fourth Proportional to 1,284.48, 1,772.72 and 787.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,284.48 : 1,772.72 = 787.18 : x
2. Step 2: Convert to fraction form
   1,284.48/1,772.72 = 787.18/x
3. Step 3: Cross multiply
   1,284.48x = 1,772.72 × 787.18
4. Step 4: Simplify right side
   1,284.48x = 1,395,449.73
5. Step 5: Solve for x
   x = 1,395,449.73/1,284.48
6. Step 6: Final answer
   x = 1,086.39