Finding the Third Proportional to 629,878.50 and 648,022.50

Step by Step Solution

1. Step 1: Write the proportion equation
   629,878.50 : 648,022.50 = 648,022.50 : x
2. Step 2: Convert to fraction form
   629,878.50/648,022.50 = 648,022.50/x
3. Step 3: Cross multiply
   629,878.50x = 648,022.50 × 648,022.50
4. Step 4: Simplify right side
   629,878.50x = 419,933,160,506.25
5. Step 5: Solve for x
   x = 419,933,160,506.25/629,878.50
6. Step 6: Final answer
   x = 666,689.15