Finding the Fourth Proportional to 2,586.28, 3,879.83 and 854.50

Step by Step Solution

1. Step 1: Write the proportion equation
   2,586.28 : 3,879.83 = 854.50 : x
2. Step 2: Convert to fraction form
   2,586.28/3,879.83 = 854.50/x
3. Step 3: Cross multiply
   2,586.28x = 3,879.83 × 854.50
4. Step 4: Simplify right side
   2,586.28x = 3,315,314.74
5. Step 5: Solve for x
   x = 3,315,314.74/2,586.28
6. Step 6: Final answer
   x = 1,281.89