Finding the Third Proportional to 315,280 and 671,456

Step by Step Solution

1. Step 1: Write the proportion equation
   315,280 : 671,456 = 671,456 : x
2. Step 2: Convert to fraction form
   315,280/671,456 = 671,456/x
3. Step 3: Cross multiply
   315,280x = 671,456 × 671,456
4. Step 4: Simplify right side
   315,280x = 450,853,159,936
5. Step 5: Solve for x
   x = 450,853,159,936/315,280
6. Step 6: Final answer
   x = 1,430,008.75