Finding the Fourth Proportional to 1,081.76, 1,618.32 and 865.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,081.76 : 1,618.32 = 865.76 : x
2. Step 2: Convert to fraction form
   1,081.76/1,618.32 = 865.76/x
3. Step 3: Cross multiply
   1,081.76x = 1,618.32 × 865.76
4. Step 4: Simplify right side
   1,081.76x = 1,401,076.72
5. Step 5: Solve for x
   x = 1,401,076.72/1,081.76
6. Step 6: Final answer
   x = 1,295.18