Finding the Fourth Proportional to 85.64, 128.42 and 34.27

Step by Step Solution

1. Step 1: Write the proportion equation
   85.64 : 128.42 = 34.27 : x
2. Step 2: Convert to fraction form
   85.64/128.42 = 34.27/x
3. Step 3: Cross multiply
   85.64x = 128.42 × 34.27
4. Step 4: Simplify right side
   85.64x = 4,401.31
5. Step 5: Solve for x
   x = 4,401.31/85.64
6. Step 6: Final answer
   x = 51.39