Finding the Third Proportional to 12,856 and 19,688

Step by Step Solution

1. Step 1: Write the proportion equation
   12,856 : 19,688 = 19,688 : x
2. Step 2: Convert to fraction form
   12,856/19,688 = 19,688/x
3. Step 3: Cross multiply
   12,856x = 19,688 × 19,688
4. Step 4: Simplify right side
   12,856x = 387,617,344
5. Step 5: Solve for x
   x = 387,617,344/12,856
6. Step 6: Final answer
   x = 30,150.70