Finding the Third Proportional to 315.14 and 638.82

Step by Step Solution

1. Step 1: Write the proportion equation
   315.14 : 638.82 = 638.82 : x
2. Step 2: Convert to fraction form
   315.14/638.82 = 638.82/x
3. Step 3: Cross multiply
   315.14x = 638.82 × 638.82
4. Step 4: Simplify right side
   315.14x = 408,096.38
5. Step 5: Solve for x
   x = 408,096.38/315.14
6. Step 6: Final answer
   x = 1,294.97