Finding the Third Proportional to 60.56 and 128.91

Step by Step Solution

1. Step 1: Write the proportion equation
   60.56 : 128.91 = 128.91 : x
2. Step 2: Convert to fraction form
   60.56/128.91 = 128.91/x
3. Step 3: Cross multiply
   60.56x = 128.91 × 128.91
4. Step 4: Simplify right side
   60.56x = 16,616.82
5. Step 5: Solve for x
   x = 16,616.82/60.56
6. Step 6: Final answer
   x = 274.37