Finding the Fourth Proportional to 2,400.72, 3,601.68 and 861.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,400.72 : 3,601.68 = 861.72 : x
2. Step 2: Convert to fraction form
   2,400.72/3,601.68 = 861.72/x
3. Step 3: Cross multiply
   2,400.72x = 3,601.68 × 861.72
4. Step 4: Simplify right side
   2,400.72x = 3,103,639.69
5. Step 5: Solve for x
   x = 3,103,639.69/2,400.72
6. Step 6: Final answer
   x = 1,292.80