Finding the Third Proportional to 85.85 and 128.88

Step by Step Solution

1. Step 1: Write the proportion equation
   85.85 : 128.88 = 128.88 : x
2. Step 2: Convert to fraction form
   85.85/128.88 = 128.88/x
3. Step 3: Cross multiply
   85.85x = 128.88 × 128.88
4. Step 4: Simplify right side
   85.85x = 16,610.78
5. Step 5: Solve for x
   x = 16,610.78/85.85
6. Step 6: Final answer
   x = 193.48