Finding the Fourth Proportional to 85.32, 128.68 and 82.88

Step by Step Solution

1. Step 1: Write the proportion equation
   85.32 : 128.68 = 82.88 : x
2. Step 2: Convert to fraction form
   85.32/128.68 = 82.88/x
3. Step 3: Cross multiply
   85.32x = 128.68 × 82.88
4. Step 4: Simplify right side
   85.32x = 10,665.00
5. Step 5: Solve for x
   x = 10,665.00/85.32
6. Step 6: Final answer
   x = 125.00