Finding the Fourth Proportional to 85.85, 128.52 and 55.33

Step by Step Solution

1. Step 1: Write the proportion equation
   85.85 : 128.52 = 55.33 : x
2. Step 2: Convert to fraction form
   85.85/128.52 = 55.33/x
3. Step 3: Cross multiply
   85.85x = 128.52 × 55.33
4. Step 4: Simplify right side
   85.85x = 7,110.69
5. Step 5: Solve for x
   x = 7,110.69/85.85
6. Step 6: Final answer
   x = 82.82