Finding the Third Proportional to 13,188 and 20,109

Step by Step Solution

1. Step 1: Write the proportion equation
   13,188 : 20,109 = 20,109 : x
2. Step 2: Convert to fraction form
   13,188/20,109 = 20,109/x
3. Step 3: Cross multiply
   13,188x = 20,109 × 20,109
4. Step 4: Simplify right side
   13,188x = 404,371,881
5. Step 5: Solve for x
   x = 404,371,881/13,188
6. Step 6: Final answer
   x = 30,662.11