Finding the Fourth Proportional to 2,619.96, 3,930.43 and 865.09

Step by Step Solution

1. Step 1: Write the proportion equation
   2,619.96 : 3,930.43 = 865.09 : x
2. Step 2: Convert to fraction form
   2,619.96/3,930.43 = 865.09/x
3. Step 3: Cross multiply
   2,619.96x = 3,930.43 × 865.09
4. Step 4: Simplify right side
   2,619.96x = 3,400,151.71
5. Step 5: Solve for x
   x = 3,400,151.71/2,619.96
6. Step 6: Final answer
   x = 1,297.79