Finding the Fourth Proportional to 85.82, 128.69 and 40.16

Step by Step Solution

1. Step 1: Write the proportion equation
   85.82 : 128.69 = 40.16 : x
2. Step 2: Convert to fraction form
   85.82/128.69 = 40.16/x
3. Step 3: Cross multiply
   85.82x = 128.69 × 40.16
4. Step 4: Simplify right side
   85.82x = 5,167.65
5. Step 5: Solve for x
   x = 5,167.65/85.82
6. Step 6: Final answer
   x = 60.21