Finding the Third Proportional to 136.37 and 256.61

Step by Step Solution

1. Step 1: Write the proportion equation
   136.37 : 256.61 = 256.61 : x
2. Step 2: Convert to fraction form
   136.37/256.61 = 256.61/x
3. Step 3: Cross multiply
   136.37x = 256.61 × 256.61
4. Step 4: Simplify right side
   136.37x = 65,846.37
5. Step 5: Solve for x
   x = 65,846.37/136.37
6. Step 6: Final answer
   x = 482.85