Finding the Third Proportional to 142.70 and 308.18

Step by Step Solution

1. Step 1: Write the proportion equation
   142.70 : 308.18 = 308.18 : x
2. Step 2: Convert to fraction form
   142.70/308.18 = 308.18/x
3. Step 3: Cross multiply
   142.70x = 308.18 × 308.18
4. Step 4: Simplify right side
   142.70x = 94,974.72
5. Step 5: Solve for x
   x = 94,974.72/142.70
6. Step 6: Final answer
   x = 665.56