Finding the Fourth Proportional to 8,581.69, 12,865.15 and 3,391.21

Step by Step Solution

1. Step 1: Write the proportion equation
   8,581.69 : 12,865.15 = 3,391.21 : x
2. Step 2: Convert to fraction form
   8,581.69/12,865.15 = 3,391.21/x
3. Step 3: Cross multiply
   8,581.69x = 12,865.15 × 3,391.21
4. Step 4: Simplify right side
   8,581.69x = 43,628,425.33
5. Step 5: Solve for x
   x = 43,628,425.33/8,581.69
6. Step 6: Final answer
   x = 5,083.90