Finding the Third Proportional to 21,320 and 31,980

Step by Step Solution

1. Step 1: Write the proportion equation
   21,320 : 31,980 = 31,980 : x
2. Step 2: Convert to fraction form
   21,320/31,980 = 31,980/x
3. Step 3: Cross multiply
   21,320x = 31,980 × 31,980
4. Step 4: Simplify right side
   21,320x = 1,022,720,400
5. Step 5: Solve for x
   x = 1,022,720,400/21,320
6. Step 6: Final answer
   x = 47,970