Finding the Third Proportional to 16,920 and 31,720

Step by Step Solution

1. Step 1: Write the proportion equation
   16,920 : 31,720 = 31,720 : x
2. Step 2: Convert to fraction form
   16,920/31,720 = 31,720/x
3. Step 3: Cross multiply
   16,920x = 31,720 × 31,720
4. Step 4: Simplify right side
   16,920x = 1,006,158,400
5. Step 5: Solve for x
   x = 1,006,158,400/16,920
6. Step 6: Final answer
   x = 59,465.63