Finding the Third Proportional to 289,906 and 443,505

Step by Step Solution

1. Step 1: Write the proportion equation
   289,906 : 443,505 = 443,505 : x
2. Step 2: Convert to fraction form
   289,906/443,505 = 443,505/x
3. Step 3: Cross multiply
   289,906x = 443,505 × 443,505
4. Step 4: Simplify right side
   289,906x = 196,696,685,025
5. Step 5: Solve for x
   x = 196,696,685,025/289,906
6. Step 6: Final answer
   x = 678,484.35