Finding the Fourth Proportional to 105.17, 157.89 and 82.42

Step by Step Solution

1. Step 1: Write the proportion equation
   105.17 : 157.89 = 82.42 : x
2. Step 2: Convert to fraction form
   105.17/157.89 = 82.42/x
3. Step 3: Cross multiply
   105.17x = 157.89 × 82.42
4. Step 4: Simplify right side
   105.17x = 13,013.49
5. Step 5: Solve for x
   x = 13,013.49/105.17
6. Step 6: Final answer
   x = 123.74