Finding the Third Proportional to 289,908 and 443,508

Step by Step Solution

1. Step 1: Write the proportion equation
   289,908 : 443,508 = 443,508 : x
2. Step 2: Convert to fraction form
   289,908/443,508 = 443,508/x
3. Step 3: Cross multiply
   289,908x = 443,508 × 443,508
4. Step 4: Simplify right side
   289,908x = 196,699,346,064
5. Step 5: Solve for x
   x = 196,699,346,064/289,908
6. Step 6: Final answer
   x = 678,488.85