Finding the Fourth Proportional to 2,811.94, 4,218.10 and 865.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,811.94 : 4,218.10 = 865.50 : x
2. Step 2: Convert to fraction form
   2,811.94/4,218.10 = 865.50/x
3. Step 3: Cross multiply
   2,811.94x = 4,218.10 × 865.50
4. Step 4: Simplify right side
   2,811.94x = 3,650,765.55
5. Step 5: Solve for x
   x = 3,650,765.55/2,811.94
6. Step 6: Final answer
   x = 1,298.31