Finding the Third Proportional to 10,143 and 13,689

Step by Step Solution

1. Step 1: Write the proportion equation
   10,143 : 13,689 = 13,689 : x
2. Step 2: Convert to fraction form
   10,143/13,689 = 13,689/x
3. Step 3: Cross multiply
   10,143x = 13,689 × 13,689
4. Step 4: Simplify right side
   10,143x = 187,388,721
5. Step 5: Solve for x
   x = 187,388,721/10,143
6. Step 6: Final answer
   x = 18,474.68