Finding the Third Proportional to 310,621.50 and 679,401

Step by Step Solution

1. Step 1: Write the proportion equation
   310,621.50 : 679,401 = 679,401 : x
2. Step 2: Convert to fraction form
   310,621.50/679,401 = 679,401/x
3. Step 3: Cross multiply
   310,621.50x = 679,401 × 679,401
4. Step 4: Simplify right side
   310,621.50x = 461,585,718,801
5. Step 5: Solve for x
   x = 461,585,718,801/310,621.50
6. Step 6: Final answer
   x = 1,486,006.99