Finding the Third Proportional to 142,139.25 and 309,334.50

Step by Step Solution

1. Step 1: Write the proportion equation
   142,139.25 : 309,334.50 = 309,334.50 : x
2. Step 2: Convert to fraction form
   142,139.25/309,334.50 = 309,334.50/x
3. Step 3: Cross multiply
   142,139.25x = 309,334.50 × 309,334.50
4. Step 4: Simplify right side
   142,139.25x = 95,687,832,890.25
5. Step 5: Solve for x
   x = 95,687,832,890.25/142,139.25
6. Step 6: Final answer
   x = 673,197.82