Finding the Third Proportional to 8,555 and 10,421

Step by Step Solution

1. Step 1: Write the proportion equation
   8,555 : 10,421 = 10,421 : x
2. Step 2: Convert to fraction form
   8,555/10,421 = 10,421/x
3. Step 3: Cross multiply
   8,555x = 10,421 × 10,421
4. Step 4: Simplify right side
   8,555x = 108,597,241
5. Step 5: Solve for x
   x = 108,597,241/8,555
6. Step 6: Final answer
   x = 12,694.01