Finding the Third Proportional to 311,972 and 638,732

Step by Step Solution

1. Step 1: Write the proportion equation
   311,972 : 638,732 = 638,732 : x
2. Step 2: Convert to fraction form
   311,972/638,732 = 638,732/x
3. Step 3: Cross multiply
   311,972x = 638,732 × 638,732
4. Step 4: Simplify right side
   311,972x = 407,978,567,824
5. Step 5: Solve for x
   x = 407,978,567,824/311,972
6. Step 6: Final answer
   x = 1,307,740.98