Finding the Fourth Proportional to 105.26, 145.25 and 72.45

Step by Step Solution

1. Step 1: Write the proportion equation
   105.26 : 145.25 = 72.45 : x
2. Step 2: Convert to fraction form
   105.26/145.25 = 72.45/x
3. Step 3: Cross multiply
   105.26x = 145.25 × 72.45
4. Step 4: Simplify right side
   105.26x = 10,523.54
5. Step 5: Solve for x
   x = 10,523.54/105.26
6. Step 6: Final answer
   x = 99.98