Finding the Fourth Proportional to 105.42, 158.04 and 57.30

Step by Step Solution

1. Step 1: Write the proportion equation
   105.42 : 158.04 = 57.30 : x
2. Step 2: Convert to fraction form
   105.42/158.04 = 57.30/x
3. Step 3: Cross multiply
   105.42x = 158.04 × 57.30
4. Step 4: Simplify right side
   105.42x = 9,055.69
5. Step 5: Solve for x
   x = 9,055.69/105.42
6. Step 6: Final answer
   x = 85.90