Finding the Fourth Proportional to 105.72, 145.92 and 68.94

Step by Step Solution

1. Step 1: Write the proportion equation
   105.72 : 145.92 = 68.94 : x
2. Step 2: Convert to fraction form
   105.72/145.92 = 68.94/x
3. Step 3: Cross multiply
   105.72x = 145.92 × 68.94
4. Step 4: Simplify right side
   105.72x = 10,059.72
5. Step 5: Solve for x
   x = 10,059.72/105.72
6. Step 6: Final answer
   x = 95.15