Finding the Third Proportional to 10,686 and 21,372

Step by Step Solution

1. Step 1: Write the proportion equation
   10,686 : 21,372 = 21,372 : x
2. Step 2: Convert to fraction form
   10,686/21,372 = 21,372/x
3. Step 3: Cross multiply
   10,686x = 21,372 × 21,372
4. Step 4: Simplify right side
   10,686x = 456,762,384
5. Step 5: Solve for x
   x = 456,762,384/10,686
6. Step 6: Final answer
   x = 42,744