Finding the Fourth Proportional to 2,619.20, 3,929.22 and 863.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,619.20 : 3,929.22 = 863.69 : x
2. Step 2: Convert to fraction form
   2,619.20/3,929.22 = 863.69/x
3. Step 3: Cross multiply
   2,619.20x = 3,929.22 × 863.69
4. Step 4: Simplify right side
   2,619.20x = 3,393,608.38
5. Step 5: Solve for x
   x = 3,393,608.38/2,619.20
6. Step 6: Final answer
   x = 1,295.67