Finding the Fourth Proportional to 105.72, 158.56 and 65.39

Step by Step Solution

1. Step 1: Write the proportion equation
   105.72 : 158.56 = 65.39 : x
2. Step 2: Convert to fraction form
   105.72/158.56 = 65.39/x
3. Step 3: Cross multiply
   105.72x = 158.56 × 65.39
4. Step 4: Simplify right side
   105.72x = 10,367.28
5. Step 5: Solve for x
   x = 10,367.28/105.72
6. Step 6: Final answer
   x = 98.07