Finding the Third Proportional to 142,870 and 313,945

Step by Step Solution

1. Step 1: Write the proportion equation
   142,870 : 313,945 = 313,945 : x
2. Step 2: Convert to fraction form
   142,870/313,945 = 313,945/x
3. Step 3: Cross multiply
   142,870x = 313,945 × 313,945
4. Step 4: Simplify right side
   142,870x = 98,561,463,025
5. Step 5: Solve for x
   x = 98,561,463,025/142,870
6. Step 6: Final answer
   x = 689,868.15