Finding the Fourth Proportional to 2,840.10, 3,866.78 and 2,831.32

Step by Step Solution

1. Step 1: Write the proportion equation
   2,840.10 : 3,866.78 = 2,831.32 : x
2. Step 2: Convert to fraction form
   2,840.10/3,866.78 = 2,831.32/x
3. Step 3: Cross multiply
   2,840.10x = 3,866.78 × 2,831.32
4. Step 4: Simplify right side
   2,840.10x = 10,948,091.55
5. Step 5: Solve for x
   x = 10,948,091.55/2,840.10
6. Step 6: Final answer
   x = 3,854.83