Finding the Third Proportional to 144,822.75 and 315,390

Step by Step Solution

1. Step 1: Write the proportion equation
   144,822.75 : 315,390 = 315,390 : x
2. Step 2: Convert to fraction form
   144,822.75/315,390 = 315,390/x
3. Step 3: Cross multiply
   144,822.75x = 315,390 × 315,390
4. Step 4: Simplify right side
   144,822.75x = 99,470,852,100
5. Step 5: Solve for x
   x = 99,470,852,100/144,822.75
6. Step 6: Final answer
   x = 686,845.49