Finding the Third Proportional to 311,932.50 and 638,619

Step by Step Solution

1. Step 1: Write the proportion equation
   311,932.50 : 638,619 = 638,619 : x
2. Step 2: Convert to fraction form
   311,932.50/638,619 = 638,619/x
3. Step 3: Cross multiply
   311,932.50x = 638,619 × 638,619
4. Step 4: Simplify right side
   311,932.50x = 407,834,227,161
5. Step 5: Solve for x
   x = 407,834,227,161/311,932.50
6. Step 6: Final answer
   x = 1,307,443.84