Finding the Third Proportional to 8,142 and 12,645

Step by Step Solution

1. Step 1: Write the proportion equation
   8,142 : 12,645 = 12,645 : x
2. Step 2: Convert to fraction form
   8,142/12,645 = 12,645/x
3. Step 3: Cross multiply
   8,142x = 12,645 × 12,645
4. Step 4: Simplify right side
   8,142x = 159,896,025
5. Step 5: Solve for x
   x = 159,896,025/8,142
6. Step 6: Final answer
   x = 19,638.42