Finding the Third Proportional to 311,958 and 638,671.50

Step by Step Solution

1. Step 1: Write the proportion equation
   311,958 : 638,671.50 = 638,671.50 : x
2. Step 2: Convert to fraction form
   311,958/638,671.50 = 638,671.50/x
3. Step 3: Cross multiply
   311,958x = 638,671.50 × 638,671.50
4. Step 4: Simplify right side
   311,958x = 407,901,284,912.25
5. Step 5: Solve for x
   x = 407,901,284,912.25/311,958
6. Step 6: Final answer
   x = 1,307,551.93