Finding the Third Proportional to 6,399 and 13,980

Step by Step Solution

1. Step 1: Write the proportion equation
   6,399 : 13,980 = 13,980 : x
2. Step 2: Convert to fraction form
   6,399/13,980 = 13,980/x
3. Step 3: Cross multiply
   6,399x = 13,980 × 13,980
4. Step 4: Simplify right side
   6,399x = 195,440,400
5. Step 5: Solve for x
   x = 195,440,400/6,399
6. Step 6: Final answer
   x = 30,542.33