Finding the Third Proportional to 6,400 and 13,920

Step by Step Solution

1. Step 1: Write the proportion equation
   6,400 : 13,920 = 13,920 : x
2. Step 2: Convert to fraction form
   6,400/13,920 = 13,920/x
3. Step 3: Cross multiply
   6,400x = 13,920 × 13,920
4. Step 4: Simplify right side
   6,400x = 193,766,400
5. Step 5: Solve for x
   x = 193,766,400/6,400
6. Step 6: Final answer
   x = 30,276