Finding the Fourth Proportional to 2,586.69, 3,879.72 and 855.27

Step by Step Solution

1. Step 1: Write the proportion equation
   2,586.69 : 3,879.72 = 855.27 : x
2. Step 2: Convert to fraction form
   2,586.69/3,879.72 = 855.27/x
3. Step 3: Cross multiply
   2,586.69x = 3,879.72 × 855.27
4. Step 4: Simplify right side
   2,586.69x = 3,318,208.12
5. Step 5: Solve for x
   x = 3,318,208.12/2,586.69
6. Step 6: Final answer
   x = 1,282.80