Finding the Fourth Proportional to 105.42, 145.53 and 82.05

Step by Step Solution

1. Step 1: Write the proportion equation
   105.42 : 145.53 = 82.05 : x
2. Step 2: Convert to fraction form
   105.42/145.53 = 82.05/x
3. Step 3: Cross multiply
   105.42x = 145.53 × 82.05
4. Step 4: Simplify right side
   105.42x = 11,940.74
5. Step 5: Solve for x
   x = 11,940.74/105.42
6. Step 6: Final answer
   x = 113.27