Finding the Third Proportional to 10,209 and 21,057

Step by Step Solution

1. Step 1: Write the proportion equation
   10,209 : 21,057 = 21,057 : x
2. Step 2: Convert to fraction form
   10,209/21,057 = 21,057/x
3. Step 3: Cross multiply
   10,209x = 21,057 × 21,057
4. Step 4: Simplify right side
   10,209x = 443,397,249
5. Step 5: Solve for x
   x = 443,397,249/10,209
6. Step 6: Final answer
   x = 43,432.00