Finding the Fourth Proportional to 85.35, 128.08 and 42.03

Step by Step Solution

1. Step 1: Write the proportion equation
   85.35 : 128.08 = 42.03 : x
2. Step 2: Convert to fraction form
   85.35/128.08 = 42.03/x
3. Step 3: Cross multiply
   85.35x = 128.08 × 42.03
4. Step 4: Simplify right side
   85.35x = 5,382.56
5. Step 5: Solve for x
   x = 5,382.56/85.35
6. Step 6: Final answer
   x = 63.06