Finding the Fourth Proportional to 2,616.96, 3,925.18 and 861.91

Step by Step Solution

1. Step 1: Write the proportion equation
   2,616.96 : 3,925.18 = 861.91 : x
2. Step 2: Convert to fraction form
   2,616.96/3,925.18 = 861.91/x
3. Step 3: Cross multiply
   2,616.96x = 3,925.18 × 861.91
4. Step 4: Simplify right side
   2,616.96x = 3,383,151.89
5. Step 5: Solve for x
   x = 3,383,151.89/2,616.96
6. Step 6: Final answer
   x = 1,292.78