Finding the Third Proportional to 106.50 and 128.06

Step by Step Solution

1. Step 1: Write the proportion equation
   106.50 : 128.06 = 128.06 : x
2. Step 2: Convert to fraction form
   106.50/128.06 = 128.06/x
3. Step 3: Cross multiply
   106.50x = 128.06 × 128.06
4. Step 4: Simplify right side
   106.50x = 16,400.00
5. Step 5: Solve for x
   x = 16,400.00/106.50
6. Step 6: Final answer
   x = 153.99