Finding the Third Proportional to 142,872 and 311,140

Step by Step Solution

1. Step 1: Write the proportion equation
   142,872 : 311,140 = 311,140 : x
2. Step 2: Convert to fraction form
   142,872/311,140 = 311,140/x
3. Step 3: Cross multiply
   142,872x = 311,140 × 311,140
4. Step 4: Simplify right side
   142,872x = 96,808,099,600
5. Step 5: Solve for x
   x = 96,808,099,600/142,872
6. Step 6: Final answer
   x = 677,586.23