Finding the Third Proportional to 308.50 and 666.38

Step by Step Solution

1. Step 1: Write the proportion equation
   308.50 : 666.38 = 666.38 : x
2. Step 2: Convert to fraction form
   308.50/666.38 = 666.38/x
3. Step 3: Cross multiply
   308.50x = 666.38 × 666.38
4. Step 4: Simplify right side
   308.50x = 444,055.64
5. Step 5: Solve for x
   x = 444,055.64/308.50
6. Step 6: Final answer
   x = 1,439.40