Finding the Third Proportional to 142,418 and 311,436

Step by Step Solution

1. Step 1: Write the proportion equation
   142,418 : 311,436 = 311,436 : x
2. Step 2: Convert to fraction form
   142,418/311,436 = 311,436/x
3. Step 3: Cross multiply
   142,418x = 311,436 × 311,436
4. Step 4: Simplify right side
   142,418x = 96,992,382,096
5. Step 5: Solve for x
   x = 96,992,382,096/142,418
6. Step 6: Final answer
   x = 681,040.19