Finding the Fourth Proportional to 85.73, 128.59 and 40.10

Step by Step Solution

1. Step 1: Write the proportion equation
   85.73 : 128.59 = 40.10 : x
2. Step 2: Convert to fraction form
   85.73/128.59 = 40.10/x
3. Step 3: Cross multiply
   85.73x = 128.59 × 40.10
4. Step 4: Simplify right side
   85.73x = 5,155.72
5. Step 5: Solve for x
   x = 5,155.72/85.73
6. Step 6: Final answer
   x = 60.14