Finding the Third Proportional to 10.50 and 20.31

Step by Step Solution

1. Step 1: Write the proportion equation
   10.50 : 20.31 = 20.31 : x
2. Step 2: Convert to fraction form
   10.50/20.31 = 20.31/x
3. Step 3: Cross multiply
   10.50x = 20.31 × 20.31
4. Step 4: Simplify right side
   10.50x = 412.60
5. Step 5: Solve for x
   x = 412.60/10.50
6. Step 6: Final answer
   x = 39.30