Finding the Fourth Proportional to 1,081.27, 1,618.84 and 840.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.27 : 1,618.84 = 840.61 : x
2. Step 2: Convert to fraction form
   1,081.27/1,618.84 = 840.61/x
3. Step 3: Cross multiply
   1,081.27x = 1,618.84 × 840.61
4. Step 4: Simplify right side
   1,081.27x = 1,360,802.90
5. Step 5: Solve for x
   x = 1,360,802.90/1,081.27
6. Step 6: Final answer
   x = 1,258.53