Finding the Third Proportional to 315,256 and 691,760

Step by Step Solution

1. Step 1: Write the proportion equation
   315,256 : 691,760 = 691,760 : x
2. Step 2: Convert to fraction form
   315,256/691,760 = 691,760/x
3. Step 3: Cross multiply
   315,256x = 691,760 × 691,760
4. Step 4: Simplify right side
   315,256x = 478,531,897,600
5. Step 5: Solve for x
   x = 478,531,897,600/315,256
6. Step 6: Final answer
   x = 1,517,915.27