Finding the Third Proportional to 311,982.75 and 638,748

Step by Step Solution

1. Step 1: Write the proportion equation
   311,982.75 : 638,748 = 638,748 : x
2. Step 2: Convert to fraction form
   311,982.75/638,748 = 638,748/x
3. Step 3: Cross multiply
   311,982.75x = 638,748 × 638,748
4. Step 4: Simplify right side
   311,982.75x = 407,999,007,504
5. Step 5: Solve for x
   x = 407,999,007,504/311,982.75
6. Step 6: Final answer
   x = 1,307,761.43