Finding the Fourth Proportional to 105.37, 145.29 and 72.56

Step by Step Solution

1. Step 1: Write the proportion equation
   105.37 : 145.29 = 72.56 : x
2. Step 2: Convert to fraction form
   105.37/145.29 = 72.56/x
3. Step 3: Cross multiply
   105.37x = 145.29 × 72.56
4. Step 4: Simplify right side
   105.37x = 10,542.88
5. Step 5: Solve for x
   x = 10,542.88/105.37
6. Step 6: Final answer
   x = 100.06