Finding the Third Proportional to 30,720 and 67,992

Step by Step Solution

1. Step 1: Write the proportion equation
   30,720 : 67,992 = 67,992 : x
2. Step 2: Convert to fraction form
   30,720/67,992 = 67,992/x
3. Step 3: Cross multiply
   30,720x = 67,992 × 67,992
4. Step 4: Simplify right side
   30,720x = 4,622,912,064
5. Step 5: Solve for x
   x = 4,622,912,064/30,720
6. Step 6: Final answer
   x = 150,485.42