Finding the Fourth Proportional to 12,638.15, 17,443.30 and 8,664.49

Step by Step Solution

1. Step 1: Write the proportion equation
   12,638.15 : 17,443.30 = 8,664.49 : x
2. Step 2: Convert to fraction form
   12,638.15/17,443.30 = 8,664.49/x
3. Step 3: Cross multiply
   12,638.15x = 17,443.30 × 8,664.49
4. Step 4: Simplify right side
   12,638.15x = 151,137,211.20
5. Step 5: Solve for x
   x = 151,137,211.20/12,638.15
6. Step 6: Final answer
   x = 11,958.81