Finding the Fourth Proportional to 105.18, 145.12 and 72.52

Step by Step Solution

1. Step 1: Write the proportion equation
   105.18 : 145.12 = 72.52 : x
2. Step 2: Convert to fraction form
   105.18/145.12 = 72.52/x
3. Step 3: Cross multiply
   105.18x = 145.12 × 72.52
4. Step 4: Simplify right side
   105.18x = 10,524.10
5. Step 5: Solve for x
   x = 10,524.10/105.18
6. Step 6: Final answer
   x = 100.06