Finding the Third Proportional to 401,861.25 and 621,688.50

Step by Step Solution

1. Step 1: Write the proportion equation
   401,861.25 : 621,688.50 = 621,688.50 : x
2. Step 2: Convert to fraction form
   401,861.25/621,688.50 = 621,688.50/x
3. Step 3: Cross multiply
   401,861.25x = 621,688.50 × 621,688.50
4. Step 4: Simplify right side
   401,861.25x = 386,496,591,032.25
5. Step 5: Solve for x
   x = 386,496,591,032.25/401,861.25
6. Step 6: Final answer
   x = 961,766.26