Finding the Third Proportional to 405,720 and 630,705.50

Step by Step Solution

1. Step 1: Write the proportion equation
   405,720 : 630,705.50 = 630,705.50 : x
2. Step 2: Convert to fraction form
   405,720/630,705.50 = 630,705.50/x
3. Step 3: Cross multiply
   405,720x = 630,705.50 × 630,705.50
4. Step 4: Simplify right side
   405,720x = 397,789,427,730.25
5. Step 5: Solve for x
   x = 397,789,427,730.25/405,720
6. Step 6: Final answer
   x = 980,453.09