Finding the Third Proportional to 309,118 and 490,404

Step by Step Solution

1. Step 1: Write the proportion equation
   309,118 : 490,404 = 490,404 : x
2. Step 2: Convert to fraction form
   309,118/490,404 = 490,404/x
3. Step 3: Cross multiply
   309,118x = 490,404 × 490,404
4. Step 4: Simplify right side
   309,118x = 240,496,083,216
5. Step 5: Solve for x
   x = 240,496,083,216/309,118
6. Step 6: Final answer
   x = 778,007.37