Finding the Third Proportional to 13,709 and 21,687

Step by Step Solution

1. Step 1: Write the proportion equation
   13,709 : 21,687 = 21,687 : x
2. Step 2: Convert to fraction form
   13,709/21,687 = 21,687/x
3. Step 3: Cross multiply
   13,709x = 21,687 × 21,687
4. Step 4: Simplify right side
   13,709x = 470,325,969
5. Step 5: Solve for x
   x = 470,325,969/13,709
6. Step 6: Final answer
   x = 34,307.82