Finding the Fourth Proportional to 85.48, 128.22 and 42.14

Step by Step Solution

1. Step 1: Write the proportion equation
   85.48 : 128.22 = 42.14 : x
2. Step 2: Convert to fraction form
   85.48/128.22 = 42.14/x
3. Step 3: Cross multiply
   85.48x = 128.22 × 42.14
4. Step 4: Simplify right side
   85.48x = 5,403.19
5. Step 5: Solve for x
   x = 5,403.19/85.48
6. Step 6: Final answer
   x = 63.21