Finding the Fourth Proportional to 2,815.17, 4,222.46 and 840.82

Step by Step Solution

1. Step 1: Write the proportion equation
   2,815.17 : 4,222.46 = 840.82 : x
2. Step 2: Convert to fraction form
   2,815.17/4,222.46 = 840.82/x
3. Step 3: Cross multiply
   2,815.17x = 4,222.46 × 840.82
4. Step 4: Simplify right side
   2,815.17x = 3,550,328.82
5. Step 5: Solve for x
   x = 3,550,328.82/2,815.17
6. Step 6: Final answer
   x = 1,261.14