Finding the Third Proportional to 12,800 and 15,520

Step by Step Solution

1. Step 1: Write the proportion equation
   12,800 : 15,520 = 15,520 : x
2. Step 2: Convert to fraction form
   12,800/15,520 = 15,520/x
3. Step 3: Cross multiply
   12,800x = 15,520 × 15,520
4. Step 4: Simplify right side
   12,800x = 240,870,400
5. Step 5: Solve for x
   x = 240,870,400/12,800
6. Step 6: Final answer
   x = 18,818