Finding the Third Proportional to 142,408 and 311,416

Step by Step Solution

1. Step 1: Write the proportion equation
   142,408 : 311,416 = 311,416 : x
2. Step 2: Convert to fraction form
   142,408/311,416 = 311,416/x
3. Step 3: Cross multiply
   142,408x = 311,416 × 311,416
4. Step 4: Simplify right side
   142,408x = 96,979,925,056
5. Step 5: Solve for x
   x = 96,979,925,056/142,408
6. Step 6: Final answer
   x = 681,000.54