Finding the Third Proportional to 144,820 and 315,386

Step by Step Solution

1. Step 1: Write the proportion equation
   144,820 : 315,386 = 315,386 : x
2. Step 2: Convert to fraction form
   144,820/315,386 = 315,386/x
3. Step 3: Cross multiply
   144,820x = 315,386 × 315,386
4. Step 4: Simplify right side
   144,820x = 99,468,328,996
5. Step 5: Solve for x
   x = 99,468,328,996/144,820
6. Step 6: Final answer
   x = 686,841.11