Finding the Third Proportional to 20,128 and 31,280

Step by Step Solution

1. Step 1: Write the proportion equation
   20,128 : 31,280 = 31,280 : x
2. Step 2: Convert to fraction form
   20,128/31,280 = 31,280/x
3. Step 3: Cross multiply
   20,128x = 31,280 × 31,280
4. Step 4: Simplify right side
   20,128x = 978,438,400
5. Step 5: Solve for x
   x = 978,438,400/20,128
6. Step 6: Final answer
   x = 48,610.81