Finding the Third Proportional to 308.06 and 661.69

Step by Step Solution

1. Step 1: Write the proportion equation
   308.06 : 661.69 = 661.69 : x
2. Step 2: Convert to fraction form
   308.06/661.69 = 661.69/x
3. Step 3: Cross multiply
   308.06x = 661.69 × 661.69
4. Step 4: Simplify right side
   308.06x = 437,830.35
5. Step 5: Solve for x
   x = 437,830.35/308.06
6. Step 6: Final answer
   x = 1,421.24