Finding the Third Proportional to 209,057 and 318,500

Step by Step Solution

1. Step 1: Write the proportion equation
   209,057 : 318,500 = 318,500 : x
2. Step 2: Convert to fraction form
   209,057/318,500 = 318,500/x
3. Step 3: Cross multiply
   209,057x = 318,500 × 318,500
4. Step 4: Simplify right side
   209,057x = 101,442,250,000
5. Step 5: Solve for x
   x = 101,442,250,000/209,057
6. Step 6: Final answer
   x = 485,237.28