Finding the Third Proportional to 142,406 and 311,412

Step by Step Solution

1. Step 1: Write the proportion equation
   142,406 : 311,412 = 311,412 : x
2. Step 2: Convert to fraction form
   142,406/311,412 = 311,412/x
3. Step 3: Cross multiply
   142,406x = 311,412 × 311,412
4. Step 4: Simplify right side
   142,406x = 96,977,433,744
5. Step 5: Solve for x
   x = 96,977,433,744/142,406
6. Step 6: Final answer
   x = 680,992.61