Finding the Third Proportional to 5,142 and 10,605

Step by Step Solution

1. Step 1: Write the proportion equation
   5,142 : 10,605 = 10,605 : x
2. Step 2: Convert to fraction form
   5,142/10,605 = 10,605/x
3. Step 3: Cross multiply
   5,142x = 10,605 × 10,605
4. Step 4: Simplify right side
   5,142x = 112,466,025
5. Step 5: Solve for x
   x = 112,466,025/5,142
6. Step 6: Final answer
   x = 21,872.04