Finding the Third Proportional to 317,298 and 691,404

Step by Step Solution

1. Step 1: Write the proportion equation
   317,298 : 691,404 = 691,404 : x
2. Step 2: Convert to fraction form
   317,298/691,404 = 691,404/x
3. Step 3: Cross multiply
   317,298x = 691,404 × 691,404
4. Step 4: Simplify right side
   317,298x = 478,039,491,216
5. Step 5: Solve for x
   x = 478,039,491,216/317,298
6. Step 6: Final answer
   x = 1,506,594.72