Finding the Third Proportional to 315,096 and 691,419

Step by Step Solution

1. Step 1: Write the proportion equation
   315,096 : 691,419 = 691,419 : x
2. Step 2: Convert to fraction form
   315,096/691,419 = 691,419/x
3. Step 3: Cross multiply
   315,096x = 691,419 × 691,419
4. Step 4: Simplify right side
   315,096x = 478,060,233,561
5. Step 5: Solve for x
   x = 478,060,233,561/315,096
6. Step 6: Final answer
   x = 1,517,189.15