Finding the Fourth Proportional to 105.91, 158.55 and 65.20

Step by Step Solution

1. Step 1: Write the proportion equation
   105.91 : 158.55 = 65.20 : x
2. Step 2: Convert to fraction form
   105.91/158.55 = 65.20/x
3. Step 3: Cross multiply
   105.91x = 158.55 × 65.20
4. Step 4: Simplify right side
   105.91x = 10,337.46
5. Step 5: Solve for x
   x = 10,337.46/105.91
6. Step 6: Final answer
   x = 97.61