Finding the Fourth Proportional to 105.25, 145.24 and 72.09

Step by Step Solution

1. Step 1: Write the proportion equation
   105.25 : 145.24 = 72.09 : x
2. Step 2: Convert to fraction form
   105.25/145.24 = 72.09/x
3. Step 3: Cross multiply
   105.25x = 145.24 × 72.09
4. Step 4: Simplify right side
   105.25x = 10,470.58
5. Step 5: Solve for x
   x = 10,470.58/105.25
6. Step 6: Final answer
   x = 99.48