Finding the Third Proportional to 408.38 and 666.56

Step by Step Solution

1. Step 1: Write the proportion equation
   408.38 : 666.56 = 666.56 : x
2. Step 2: Convert to fraction form
   408.38/666.56 = 666.56/x
3. Step 3: Cross multiply
   408.38x = 666.56 × 666.56
4. Step 4: Simplify right side
   408.38x = 444,305.57
5. Step 5: Solve for x
   x = 444,305.57/408.38
6. Step 6: Final answer
   x = 1,087.98