Finding the Third Proportional to 8,124 and 12,921

Step by Step Solution

1. Step 1: Write the proportion equation
   8,124 : 12,921 = 12,921 : x
2. Step 2: Convert to fraction form
   8,124/12,921 = 12,921/x
3. Step 3: Cross multiply
   8,124x = 12,921 × 12,921
4. Step 4: Simplify right side
   8,124x = 166,952,241
5. Step 5: Solve for x
   x = 166,952,241/8,124
6. Step 6: Final answer
   x = 20,550.50