Finding the Third Proportional to 10,389 and 21,909

Step by Step Solution

1. Step 1: Write the proportion equation
   10,389 : 21,909 = 21,909 : x
2. Step 2: Convert to fraction form
   10,389/21,909 = 21,909/x
3. Step 3: Cross multiply
   10,389x = 21,909 × 21,909
4. Step 4: Simplify right side
   10,389x = 480,004,281
5. Step 5: Solve for x
   x = 480,004,281/10,389
6. Step 6: Final answer
   x = 46,203.13