Finding the Third Proportional to 10,155 and 20,721

Step by Step Solution

1. Step 1: Write the proportion equation
   10,155 : 20,721 = 20,721 : x
2. Step 2: Convert to fraction form
   10,155/20,721 = 20,721/x
3. Step 3: Cross multiply
   10,155x = 20,721 × 20,721
4. Step 4: Simplify right side
   10,155x = 429,359,841
5. Step 5: Solve for x
   x = 429,359,841/10,155
6. Step 6: Final answer
   x = 42,280.63