Finding the Third Proportional to 8,790 and 12,705

Step by Step Solution

1. Step 1: Write the proportion equation
   8,790 : 12,705 = 12,705 : x
2. Step 2: Convert to fraction form
   8,790/12,705 = 12,705/x
3. Step 3: Cross multiply
   8,790x = 12,705 × 12,705
4. Step 4: Simplify right side
   8,790x = 161,417,025
5. Step 5: Solve for x
   x = 161,417,025/8,790
6. Step 6: Final answer
   x = 18,363.71