Finding the Third Proportional to 312,823.50 and 682,978.50

Step by Step Solution

1. Step 1: Write the proportion equation
   312,823.50 : 682,978.50 = 682,978.50 : x
2. Step 2: Convert to fraction form
   312,823.50/682,978.50 = 682,978.50/x
3. Step 3: Cross multiply
   312,823.50x = 682,978.50 × 682,978.50
4. Step 4: Simplify right side
   312,823.50x = 466,459,631,462.25
5. Step 5: Solve for x
   x = 466,459,631,462.25/312,823.50
6. Step 6: Final answer
   x = 1,491,127.21