Finding the Third Proportional to 297,874 and 642,404

Step by Step Solution

1. Step 1: Write the proportion equation
   297,874 : 642,404 = 642,404 : x
2. Step 2: Convert to fraction form
   297,874/642,404 = 642,404/x
3. Step 3: Cross multiply
   297,874x = 642,404 × 642,404
4. Step 4: Simplify right side
   297,874x = 412,682,899,216
5. Step 5: Solve for x
   x = 412,682,899,216/297,874
6. Step 6: Final answer
   x = 1,385,427.73