Finding the Third Proportional to 312,639 and 682,480.50

Step by Step Solution

1. Step 1: Write the proportion equation
   312,639 : 682,480.50 = 682,480.50 : x
2. Step 2: Convert to fraction form
   312,639/682,480.50 = 682,480.50/x
3. Step 3: Cross multiply
   312,639x = 682,480.50 × 682,480.50
4. Step 4: Simplify right side
   312,639x = 465,779,632,880.25
5. Step 5: Solve for x
   x = 465,779,632,880.25/312,639
6. Step 6: Final answer
   x = 1,489,832.15