Finding the Third Proportional to 311,113.50 and 664,872

Step by Step Solution

1. Step 1: Write the proportion equation
   311,113.50 : 664,872 = 664,872 : x
2. Step 2: Convert to fraction form
   311,113.50/664,872 = 664,872/x
3. Step 3: Cross multiply
   311,113.50x = 664,872 × 664,872
4. Step 4: Simplify right side
   311,113.50x = 442,054,776,384
5. Step 5: Solve for x
   x = 442,054,776,384/311,113.50
6. Step 6: Final answer
   x = 1,420,879.44