Finding the Fourth Proportional to 105.71, 145.87 and 72.97

Step by Step Solution

1. Step 1: Write the proportion equation
   105.71 : 145.87 = 72.97 : x
2. Step 2: Convert to fraction form
   105.71/145.87 = 72.97/x
3. Step 3: Cross multiply
   105.71x = 145.87 × 72.97
4. Step 4: Simplify right side
   105.71x = 10,643.59
5. Step 5: Solve for x
   x = 10,643.59/105.71
6. Step 6: Final answer
   x = 100.69