Finding the Third Proportional to 9,940 and 20,510

Step by Step Solution

1. Step 1: Write the proportion equation
   9,940 : 20,510 = 20,510 : x
2. Step 2: Convert to fraction form
   9,940/20,510 = 20,510/x
3. Step 3: Cross multiply
   9,940x = 20,510 × 20,510
4. Step 4: Simplify right side
   9,940x = 420,660,100
5. Step 5: Solve for x
   x = 420,660,100/9,940
6. Step 6: Final answer
   x = 42,319.93