Finding the Third Proportional to 356,810 and 489,279.50

Step by Step Solution

1. Step 1: Write the proportion equation
   356,810 : 489,279.50 = 489,279.50 : x
2. Step 2: Convert to fraction form
   356,810/489,279.50 = 489,279.50/x
3. Step 3: Cross multiply
   356,810x = 489,279.50 × 489,279.50
4. Step 4: Simplify right side
   356,810x = 239,394,429,120.25
5. Step 5: Solve for x
   x = 239,394,429,120.25/356,810
6. Step 6: Final answer
   x = 670,929.71