Finding the Third Proportional to 10,399 and 21,490

Step by Step Solution

1. Step 1: Write the proportion equation
   10,399 : 21,490 = 21,490 : x
2. Step 2: Convert to fraction form
   10,399/21,490 = 21,490/x
3. Step 3: Cross multiply
   10,399x = 21,490 × 21,490
4. Step 4: Simplify right side
   10,399x = 461,820,100
5. Step 5: Solve for x
   x = 461,820,100/10,399
6. Step 6: Final answer
   x = 44,410.05