Finding the Fourth Proportional to 8,949.96, 13,404.15 and 8,638.57

Step by Step Solution

1. Step 1: Write the proportion equation
   8,949.96 : 13,404.15 = 8,638.57 : x
2. Step 2: Convert to fraction form
   8,949.96/13,404.15 = 8,638.57/x
3. Step 3: Cross multiply
   8,949.96x = 13,404.15 × 8,638.57
4. Step 4: Simplify right side
   8,949.96x = 115,792,688.07
5. Step 5: Solve for x
   x = 115,792,688.07/8,949.96
6. Step 6: Final answer
   x = 12,937.79