Finding the Third Proportional to 308.06 and 721.78

Step by Step Solution

1. Step 1: Write the proportion equation
   308.06 : 721.78 = 721.78 : x
2. Step 2: Convert to fraction form
   308.06/721.78 = 721.78/x
3. Step 3: Cross multiply
   308.06x = 721.78 × 721.78
4. Step 4: Simplify right side
   308.06x = 520,968.17
5. Step 5: Solve for x
   x = 520,968.17/308.06
6. Step 6: Final answer
   x = 1,691.11