Finding the Third Proportional to 406,395 and 644,035.50

Step by Step Solution

1. Step 1: Write the proportion equation
   406,395 : 644,035.50 = 644,035.50 : x
2. Step 2: Convert to fraction form
   406,395/644,035.50 = 644,035.50/x
3. Step 3: Cross multiply
   406,395x = 644,035.50 × 644,035.50
4. Step 4: Simplify right side
   406,395x = 414,781,725,260.25
5. Step 5: Solve for x
   x = 414,781,725,260.25/406,395
6. Step 6: Final answer
   x = 1,020,636.88