Finding the Fourth Proportional to 105.52, 145.58 and 72.71

Step by Step Solution

1. Step 1: Write the proportion equation
   105.52 : 145.58 = 72.71 : x
2. Step 2: Convert to fraction form
   105.52/145.58 = 72.71/x
3. Step 3: Cross multiply
   105.52x = 145.58 × 72.71
4. Step 4: Simplify right side
   105.52x = 10,584.76
5. Step 5: Solve for x
   x = 10,584.76/105.52
6. Step 6: Final answer
   x = 100.32