Finding the Fourth Proportional to 2,787.86, 4,182.53 and 840.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,787.86 : 4,182.53 = 840.12 : x
2. Step 2: Convert to fraction form
   2,787.86/4,182.53 = 840.12/x
3. Step 3: Cross multiply
   2,787.86x = 4,182.53 × 840.12
4. Step 4: Simplify right side
   2,787.86x = 3,513,822.90
5. Step 5: Solve for x
   x = 3,513,822.90/2,787.86
6. Step 6: Final answer
   x = 1,260.40