Finding the Third Proportional to 21,728 and 31,920

Step by Step Solution

1. Step 1: Write the proportion equation
   21,728 : 31,920 = 31,920 : x
2. Step 2: Convert to fraction form
   21,728/31,920 = 31,920/x
3. Step 3: Cross multiply
   21,728x = 31,920 × 31,920
4. Step 4: Simplify right side
   21,728x = 1,018,886,400
5. Step 5: Solve for x
   x = 1,018,886,400/21,728
6. Step 6: Final answer
   x = 46,892.78