Finding the Third Proportional to 143,380 and 311,912

Step by Step Solution

1. Step 1: Write the proportion equation
   143,380 : 311,912 = 311,912 : x
2. Step 2: Convert to fraction form
   143,380/311,912 = 311,912/x
3. Step 3: Cross multiply
   143,380x = 311,912 × 311,912
4. Step 4: Simplify right side
   143,380x = 97,289,095,744
5. Step 5: Solve for x
   x = 97,289,095,744/143,380
6. Step 6: Final answer
   x = 678,540.21