Finding the Third Proportional to 103,639 and 221,499

Step by Step Solution

1. Step 1: Write the proportion equation
   103,639 : 221,499 = 221,499 : x
2. Step 2: Convert to fraction form
   103,639/221,499 = 221,499/x
3. Step 3: Cross multiply
   103,639x = 221,499 × 221,499
4. Step 4: Simplify right side
   103,639x = 49,061,807,001
5. Step 5: Solve for x
   x = 49,061,807,001/103,639
6. Step 6: Final answer
   x = 473,391.36