Finding the Fourth Proportional to 2,092.78, 3,139.98 and 860.77

Step by Step Solution

1. Step 1: Write the proportion equation
   2,092.78 : 3,139.98 = 860.77 : x
2. Step 2: Convert to fraction form
   2,092.78/3,139.98 = 860.77/x
3. Step 3: Cross multiply
   2,092.78x = 3,139.98 × 860.77
4. Step 4: Simplify right side
   2,092.78x = 2,702,800.58
5. Step 5: Solve for x
   x = 2,702,800.58/2,092.78
6. Step 6: Final answer
   x = 1,291.49