Finding the Fourth Proportional to 85.69, 128.41 and 42.33

Step by Step Solution

1. Step 1: Write the proportion equation
   85.69 : 128.41 = 42.33 : x
2. Step 2: Convert to fraction form
   85.69/128.41 = 42.33/x
3. Step 3: Cross multiply
   85.69x = 128.41 × 42.33
4. Step 4: Simplify right side
   85.69x = 5,435.60
5. Step 5: Solve for x
   x = 5,435.60/85.69
6. Step 6: Final answer
   x = 63.43