Finding the Fourth Proportional to 2,788.50, 4,183.43 and 840.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,788.50 : 4,183.43 = 840.72 : x
2. Step 2: Convert to fraction form
   2,788.50/4,183.43 = 840.72/x
3. Step 3: Cross multiply
   2,788.50x = 4,183.43 × 840.72
4. Step 4: Simplify right side
   2,788.50x = 3,517,089.07
5. Step 5: Solve for x
   x = 3,517,089.07/2,788.50
6. Step 6: Final answer
   x = 1,261.28