Finding the Third Proportional to 142,742.25 and 309,359.25

Step by Step Solution

1. Step 1: Write the proportion equation
   142,742.25 : 309,359.25 = 309,359.25 : x
2. Step 2: Convert to fraction form
   142,742.25/309,359.25 = 309,359.25/x
3. Step 3: Cross multiply
   142,742.25x = 309,359.25 × 309,359.25
4. Step 4: Simplify right side
   142,742.25x = 95,703,145,560.56
5. Step 5: Solve for x
   x = 95,703,145,560.56/142,742.25
6. Step 6: Final answer
   x = 670,461.24