Finding the Third Proportional to 10,129 and 21,357

Step by Step Solution

1. Step 1: Write the proportion equation
   10,129 : 21,357 = 21,357 : x
2. Step 2: Convert to fraction form
   10,129/21,357 = 21,357/x
3. Step 3: Cross multiply
   10,129x = 21,357 × 21,357
4. Step 4: Simplify right side
   10,129x = 456,121,449
5. Step 5: Solve for x
   x = 456,121,449/10,129
6. Step 6: Final answer
   x = 45,031.24