Finding the Third Proportional to 142,400 and 307,642

Step by Step Solution

1. Step 1: Write the proportion equation
   142,400 : 307,642 = 307,642 : x
2. Step 2: Convert to fraction form
   142,400/307,642 = 307,642/x
3. Step 3: Cross multiply
   142,400x = 307,642 × 307,642
4. Step 4: Simplify right side
   142,400x = 94,643,600,164
5. Step 5: Solve for x
   x = 94,643,600,164/142,400
6. Step 6: Final answer
   x = 664,632.02