Finding the Third Proportional to 255.94 and 393.69

Step by Step Solution

1. Step 1: Write the proportion equation
   255.94 : 393.69 = 393.69 : x
2. Step 2: Convert to fraction form
   255.94/393.69 = 393.69/x
3. Step 3: Cross multiply
   255.94x = 393.69 × 393.69
4. Step 4: Simplify right side
   255.94x = 154,989.85
5. Step 5: Solve for x
   x = 154,989.85/255.94
6. Step 6: Final answer
   x = 605.58