Finding the Fourth Proportional to 2,616.66, 3,925.56 and 861.59

Step by Step Solution

1. Step 1: Write the proportion equation
   2,616.66 : 3,925.56 = 861.59 : x
2. Step 2: Convert to fraction form
   2,616.66/3,925.56 = 861.59/x
3. Step 3: Cross multiply
   2,616.66x = 3,925.56 × 861.59
4. Step 4: Simplify right side
   2,616.66x = 3,382,236.29
5. Step 5: Solve for x
   x = 3,382,236.29/2,616.66
6. Step 6: Final answer
   x = 1,292.58