Finding the Third Proportional to 309,640 and 512,462

Step by Step Solution

1. Step 1: Write the proportion equation
   309,640 : 512,462 = 512,462 : x
2. Step 2: Convert to fraction form
   309,640/512,462 = 512,462/x
3. Step 3: Cross multiply
   309,640x = 512,462 × 512,462
4. Step 4: Simplify right side
   309,640x = 262,617,301,444
5. Step 5: Solve for x
   x = 262,617,301,444/309,640
6. Step 6: Final answer
   x = 848,137.52