Finding the Third Proportional to 142,912 and 311,216

Step by Step Solution

1. Step 1: Write the proportion equation
   142,912 : 311,216 = 311,216 : x
2. Step 2: Convert to fraction form
   142,912/311,216 = 311,216/x
3. Step 3: Cross multiply
   142,912x = 311,216 × 311,216
4. Step 4: Simplify right side
   142,912x = 96,855,398,656
5. Step 5: Solve for x
   x = 96,855,398,656/142,912
6. Step 6: Final answer
   x = 677,727.54