Finding the Third Proportional to 8,142 and 12,345

Step by Step Solution

1. Step 1: Write the proportion equation
   8,142 : 12,345 = 12,345 : x
2. Step 2: Convert to fraction form
   8,142/12,345 = 12,345/x
3. Step 3: Cross multiply
   8,142x = 12,345 × 12,345
4. Step 4: Simplify right side
   8,142x = 152,399,025
5. Step 5: Solve for x
   x = 152,399,025/8,142
6. Step 6: Final answer
   x = 18,717.64