Finding the Third Proportional to 256.78 and 496.69

Step by Step Solution

1. Step 1: Write the proportion equation
   256.78 : 496.69 = 496.69 : x
2. Step 2: Convert to fraction form
   256.78/496.69 = 496.69/x
3. Step 3: Cross multiply
   256.78x = 496.69 × 496.69
4. Step 4: Simplify right side
   256.78x = 246,698.47
5. Step 5: Solve for x
   x = 246,698.47/256.78
6. Step 6: Final answer
   x = 960.73