Finding the Third Proportional to 12,129 and 17,721

Step by Step Solution

1. Step 1: Write the proportion equation
   12,129 : 17,721 = 17,721 : x
2. Step 2: Convert to fraction form
   12,129/17,721 = 17,721/x
3. Step 3: Cross multiply
   12,129x = 17,721 × 17,721
4. Step 4: Simplify right side
   12,129x = 314,033,841
5. Step 5: Solve for x
   x = 314,033,841/12,129
6. Step 6: Final answer
   x = 25,891.16