Finding the Third Proportional to 30,816 and 72,720

Step by Step Solution

1. Step 1: Write the proportion equation
   30,816 : 72,720 = 72,720 : x
2. Step 2: Convert to fraction form
   30,816/72,720 = 72,720/x
3. Step 3: Cross multiply
   30,816x = 72,720 × 72,720
4. Step 4: Simplify right side
   30,816x = 5,288,198,400
5. Step 5: Solve for x
   x = 5,288,198,400/30,816
6. Step 6: Final answer
   x = 171,605.61