Finding the Fourth Proportional to 2,619.88, 3,930.31 and 865.01

Step by Step Solution

1. Step 1: Write the proportion equation
   2,619.88 : 3,930.31 = 865.01 : x
2. Step 2: Convert to fraction form
   2,619.88/3,930.31 = 865.01/x
3. Step 3: Cross multiply
   2,619.88x = 3,930.31 × 865.01
4. Step 4: Simplify right side
   2,619.88x = 3,399,745.46
5. Step 5: Solve for x
   x = 3,399,745.46/2,619.88
6. Step 6: Final answer
   x = 1,297.67