Finding the Fourth Proportional to 105.98, 158.82 and 57.20

Step by Step Solution

1. Step 1: Write the proportion equation
   105.98 : 158.82 = 57.20 : x
2. Step 2: Convert to fraction form
   105.98/158.82 = 57.20/x
3. Step 3: Cross multiply
   105.98x = 158.82 × 57.20
4. Step 4: Simplify right side
   105.98x = 9,084.50
5. Step 5: Solve for x
   x = 9,084.50/105.98
6. Step 6: Final answer
   x = 85.72