Finding the Third Proportional to 311,951 and 638,657.50

Step by Step Solution

1. Step 1: Write the proportion equation
   311,951 : 638,657.50 = 638,657.50 : x
2. Step 2: Convert to fraction form
   311,951/638,657.50 = 638,657.50/x
3. Step 3: Cross multiply
   311,951x = 638,657.50 × 638,657.50
4. Step 4: Simplify right side
   311,951x = 407,883,402,306.25
5. Step 5: Solve for x
   x = 407,883,402,306.25/311,951
6. Step 6: Final answer
   x = 1,307,523.95