Finding the Third Proportional to 142,243 and 313,123

Step by Step Solution

1. Step 1: Write the proportion equation
   142,243 : 313,123 = 313,123 : x
2. Step 2: Convert to fraction form
   142,243/313,123 = 313,123/x
3. Step 3: Cross multiply
   142,243x = 313,123 × 313,123
4. Step 4: Simplify right side
   142,243x = 98,046,013,129
5. Step 5: Solve for x
   x = 98,046,013,129/142,243
6. Step 6: Final answer
   x = 689,285.33