Finding the Third Proportional to 142,676 and 309,128.50

Step by Step Solution

1. Step 1: Write the proportion equation
   142,676 : 309,128.50 = 309,128.50 : x
2. Step 2: Convert to fraction form
   142,676/309,128.50 = 309,128.50/x
3. Step 3: Cross multiply
   142,676x = 309,128.50 × 309,128.50
4. Step 4: Simplify right side
   142,676x = 95,560,429,512.25
5. Step 5: Solve for x
   x = 95,560,429,512.25/142,676
6. Step 6: Final answer
   x = 669,772.28