Finding the Fourth Proportional to 105.42, 158.28 and 82.89

Step by Step Solution

1. Step 1: Write the proportion equation
   105.42 : 158.28 = 82.89 : x
2. Step 2: Convert to fraction form
   105.42/158.28 = 82.89/x
3. Step 3: Cross multiply
   105.42x = 158.28 × 82.89
4. Step 4: Simplify right side
   105.42x = 13,119.83
5. Step 5: Solve for x
   x = 13,119.83/105.42
6. Step 6: Final answer
   x = 124.45