Finding the Third Proportional to 12,688 and 17,208

Step by Step Solution

1. Step 1: Write the proportion equation
   12,688 : 17,208 = 17,208 : x
2. Step 2: Convert to fraction form
   12,688/17,208 = 17,208/x
3. Step 3: Cross multiply
   12,688x = 17,208 × 17,208
4. Step 4: Simplify right side
   12,688x = 296,115,264
5. Step 5: Solve for x
   x = 296,115,264/12,688
6. Step 6: Final answer
   x = 23,338.21