Finding the Third Proportional to 8,428 and 12,426

Step by Step Solution

1. Step 1: Write the proportion equation
   8,428 : 12,426 = 12,426 : x
2. Step 2: Convert to fraction form
   8,428/12,426 = 12,426/x
3. Step 3: Cross multiply
   8,428x = 12,426 × 12,426
4. Step 4: Simplify right side
   8,428x = 154,405,476
5. Step 5: Solve for x
   x = 154,405,476/8,428
6. Step 6: Final answer
   x = 18,320.54