Finding the Third Proportional to 411,321 and 621,355.50

Step by Step Solution

1. Step 1: Write the proportion equation
   411,321 : 621,355.50 = 621,355.50 : x
2. Step 2: Convert to fraction form
   411,321/621,355.50 = 621,355.50/x
3. Step 3: Cross multiply
   411,321x = 621,355.50 × 621,355.50
4. Step 4: Simplify right side
   411,321x = 386,082,657,380.25
5. Step 5: Solve for x
   x = 386,082,657,380.25/411,321
6. Step 6: Final answer
   x = 938,640.76