Finding the Third Proportional to 12,680 and 19,711

Step by Step Solution

1. Step 1: Write the proportion equation
   12,680 : 19,711 = 19,711 : x
2. Step 2: Convert to fraction form
   12,680/19,711 = 19,711/x
3. Step 3: Cross multiply
   12,680x = 19,711 × 19,711
4. Step 4: Simplify right side
   12,680x = 388,523,521
5. Step 5: Solve for x
   x = 388,523,521/12,680
6. Step 6: Final answer
   x = 30,640.66