Finding the Third Proportional to 8,211 and 12,738

Step by Step Solution

1. Step 1: Write the proportion equation
   8,211 : 12,738 = 12,738 : x
2. Step 2: Convert to fraction form
   8,211/12,738 = 12,738/x
3. Step 3: Cross multiply
   8,211x = 12,738 × 12,738
4. Step 4: Simplify right side
   8,211x = 162,256,644
5. Step 5: Solve for x
   x = 162,256,644/8,211
6. Step 6: Final answer
   x = 19,760.89