Finding the Third Proportional to 142,410 and 311,418

Step by Step Solution

1. Step 1: Write the proportion equation
   142,410 : 311,418 = 311,418 : x
2. Step 2: Convert to fraction form
   142,410/311,418 = 311,418/x
3. Step 3: Cross multiply
   142,410x = 311,418 × 311,418
4. Step 4: Simplify right side
   142,410x = 96,981,170,724
5. Step 5: Solve for x
   x = 96,981,170,724/142,410
6. Step 6: Final answer
   x = 680,999.72