Finding the Third Proportional to 258.56 and 361.69

Step by Step Solution

1. Step 1: Write the proportion equation
   258.56 : 361.69 = 361.69 : x
2. Step 2: Convert to fraction form
   258.56/361.69 = 361.69/x
3. Step 3: Cross multiply
   258.56x = 361.69 × 361.69
4. Step 4: Simplify right side
   258.56x = 130,817.85
5. Step 5: Solve for x
   x = 130,817.85/258.56
6. Step 6: Final answer
   x = 505.94