Finding the Fourth Proportional to 105.50, 145.59 and 80.55

Step by Step Solution

1. Step 1: Write the proportion equation
   105.50 : 145.59 = 80.55 : x
2. Step 2: Convert to fraction form
   105.50/145.59 = 80.55/x
3. Step 3: Cross multiply
   105.50x = 145.59 × 80.55
4. Step 4: Simplify right side
   105.50x = 11,727.27
5. Step 5: Solve for x
   x = 11,727.27/105.50
6. Step 6: Final answer
   x = 111.16